diff --git a/tests-unit/comfy_test/test_seedvr_clear_vae_memory_soft_empty_cache.py b/tests-unit/comfy_test/test_seedvr_clear_vae_memory_soft_empty_cache.py
new file mode 100644
index 000000000..82127a189
--- /dev/null
+++ b/tests-unit/comfy_test/test_seedvr_clear_vae_memory_soft_empty_cache.py
@@ -0,0 +1,61 @@
+"""Regression test for ``comfy_extras.nodes_seedvr.clear_vae_memory`` —
+must dispatch its cache clear via ``comfy.model_management.soft_empty_cache``
+rather than calling ``torch.cuda.empty_cache()`` directly. The canonical helper
+at ``comfy/model_management.py:1780`` short-circuits via ``cpu_mode()`` and
+dispatches per-backend (MPS / XPU / NPU / MLU / CUDA), so it is the only
+correct call shape on non-CUDA hosts and on managed-device hosts where
+``comfy.cli_args.args.cpu`` is True.
+"""
+
+from unittest.mock import patch
+
+import torch
+
+# CPU-only CI fix: ``comfy_extras.nodes_seedvr`` transitively imports
+# ``comfy.model_management``, whose module-level
+# ``cpu_state = CPUState.CPU if args.cpu`` initialiser
+# (``comfy/model_management.py:152-153``) reads ``comfy.cli_args.args.cpu``
+# at import time. Match the pattern at
+# ``tests-unit/comfy_test/test_seedvr_vae_decode_unpadded_t.py:33-44``: flip
+# ``args.cpu`` BEFORE importing any ``comfy.ldm.*`` or ``comfy_extras.*``
+# symbol. This module forces ``args.cpu = True`` unconditionally (rather
+# than only when ``torch.cuda.is_available()`` is False) so ``cpu_mode()``
+# returns True at call time regardless of host CUDA availability — the
+# path under test is ``soft_empty_cache``'s CPU-mode short-circuit at
+# ``comfy/model_management.py:1781``.
+from comfy.cli_args import args as _cli_args
+
+_cli_args.cpu = True
+
+import comfy.model_management  # noqa: E402
+import comfy_extras.nodes_seedvr as nodes_seedvr  # noqa: E402
+
+
+def test_clear_vae_memory_uses_soft_empty_cache():
+    """``clear_vae_memory(stub)`` must invoke
+    ``comfy.model_management.soft_empty_cache`` exactly once and
+    ``torch.cuda.empty_cache`` zero times when ``args.cpu`` is True.
+    """
+    stub = torch.nn.Module()
+
+    with patch.object(
+        comfy.model_management, "soft_empty_cache"
+    ) as soft_empty_spy, patch.object(
+        torch.cuda, "empty_cache"
+    ) as cuda_empty_spy:
+        nodes_seedvr.clear_vae_memory(stub)
+
+    assert cuda_empty_spy.call_count == 0, (
+        f"torch.cuda.empty_cache was called {cuda_empty_spy.call_count} "
+        f"times; expected 0. clear_vae_memory must dispatch via "
+        f"comfy.model_management.soft_empty_cache, which short-circuits in "
+        f"CPU mode (cpu_mode() check at comfy/model_management.py:1781). "
+        f"The unguarded torch.cuda.empty_cache() call at "
+        f"comfy_extras/nodes_seedvr.py:84 is the regression this test locks."
+    )
+    assert soft_empty_spy.call_count == 1, (
+        f"comfy.model_management.soft_empty_cache was called "
+        f"{soft_empty_spy.call_count} times; expected exactly 1. "
+        f"clear_vae_memory must dispatch its cache clear via the canonical "
+        f"per-backend helper at comfy/model_management.py:1780."
+    )
diff --git a/tests-unit/comfy_test/test_seedvr_vae_5d_tiled_decode.py b/tests-unit/comfy_test/test_seedvr_vae_5d_tiled_decode.py
new file mode 100644
index 000000000..f4a05d87f
--- /dev/null
+++ b/tests-unit/comfy_test/test_seedvr_vae_5d_tiled_decode.py
@@ -0,0 +1,356 @@
+from unittest.mock import patch
+
+import torch
+import torch.nn as nn
+
+from comfy.cli_args import args as cli_args
+
+if not torch.cuda.is_available():
+    cli_args.cpu = True
+
+import comfy.ldm.seedvr.vae as vae_mod  # noqa: E402
+import comfy.sd as sd_mod  # noqa: E402
+import nodes as nodes_mod  # noqa: E402
+
+
+def _lab_color_passthrough(content, style):
+    return content
+
+
+def _decode_fingerprint(self, z, return_dict=True):
+    b, _, t, h, w = z.shape
+    out = torch.empty(b, 3, t, h * 8, w * 8, dtype=z.dtype, device=z.device)
+    for batch_idx in range(b):
+        out[batch_idx].fill_(float(batch_idx + 1))
+    return out
+
+
+def _make_wrapper(b=2, t=3, enable_tiling=False):
+    wrapper = vae_mod.VideoAutoencoderKLWrapper.__new__(
+        vae_mod.VideoAutoencoderKLWrapper
+    )
+    nn.Module.__init__(wrapper)
+    wrapper.tiled_args = {"enable_tiling": enable_tiling}
+    wrapper.original_image_video = torch.zeros(b, 3, t, 16, 16)
+    wrapper.img_dims = (16, 16)
+    return wrapper
+
+
+def test_seedvr2_decode_accepts_5d_bcthw_latents_and_preserves_batch_time_axes():
+    wrapper = _make_wrapper(b=2, t=3, enable_tiling=False)
+    latent = torch.zeros(2, 16, 3, 2, 2)
+
+    with patch.object(vae_mod.VideoAutoencoderKL, "decode_", _decode_fingerprint), \
+         patch.object(vae_mod, "lab_color_transfer", _lab_color_passthrough):
+        out = wrapper.decode(latent)
+
+    assert tuple(out.shape) == (2, 3, 3, 16, 16)
+    assert out[0, 0, 0, 0, 0].item() == 1.0
+    assert out[1, 0, 0, 0, 0].item() == 2.0
+
+
+class _SeedVR2DecodeStub(vae_mod.VideoAutoencoderKLWrapper):
+    def __init__(self):
+        nn.Module.__init__(self)
+        self.tiled_args = {}
+        self.calls = []
+        self.original_image_video = torch.zeros(1, 3, 12, 16, 16)
+        self.spatial_downsample_factor = 8
+        self.temporal_downsample_factor = 4
+
+    def decode(self, z, seedvr2_tiling=None):
+        self.calls.append({"seedvr2_tiling": seedvr2_tiling, "shape": tuple(z.shape)})
+        return z
+
+
+def test_vae_decode_tiled_allows_zero_temporal_controls_and_passes_them_through():
+    input_types = nodes_mod.VAEDecodeTiled.INPUT_TYPES()["required"]
+    assert input_types["temporal_size"][1]["min"] == 0
+    assert input_types["temporal_overlap"][1]["min"] == 0
+    assert "SeedVR2 allows 0" in input_types["temporal_size"][1]["tooltip"]
+
+    class _DecodeRecorder:
+        def __init__(self):
+            self.calls = []
+
+        def temporal_compression_decode(self):
+            return 4
+
+        def spacial_compression_decode(self):
+            return 8
+
+        def decode_tiled(self, samples, **kwargs):
+            self.calls.append({"shape": tuple(samples.shape), **kwargs})
+            return torch.zeros(1, 8, 8, 3)
+
+    recorder = _DecodeRecorder()
+    node = nodes_mod.VAEDecodeTiled()
+
+    node.decode(
+        recorder,
+        {"samples": torch.zeros(1, 16, 3, 32, 32)},
+        tile_size=256,
+        overlap=64,
+        temporal_size=0,
+        temporal_overlap=0,
+    )
+
+    assert recorder.calls == [
+        {
+            "shape": (1, 16, 3, 32, 32),
+            "tile_x": 32,
+            "tile_y": 32,
+            "overlap": 8,
+            "tile_t": 0,
+            "overlap_t": 0,
+        }
+    ]
+
+
+def test_vae_decode_tiled_preserves_positive_overlap_after_temporal_compression():
+    class _DecodeRecorder:
+        def __init__(self):
+            self.calls = []
+
+        def temporal_compression_decode(self):
+            return 8
+
+        def spacial_compression_decode(self):
+            return 8
+
+        def decode_tiled(self, samples, **kwargs):
+            self.calls.append(kwargs)
+            return torch.zeros(1, 8, 8, 3)
+
+    recorder = _DecodeRecorder()
+
+    nodes_mod.VAEDecodeTiled().decode(
+        recorder,
+        {"samples": torch.zeros(1, 16, 3, 32, 32)},
+        tile_size=256,
+        overlap=64,
+        temporal_size=64,
+        temporal_overlap=4,
+    )
+
+    assert recorder.calls[0]["tile_t"] == 8
+    assert recorder.calls[0]["overlap_t"] == 1
+
+
+def test_seedvr2_decode_tiled_uses_seedvr2_path_not_generic_3d_tiler(monkeypatch):
+    vae = sd_mod.VAE.__new__(sd_mod.VAE)
+    vae.first_stage_model = _SeedVR2DecodeStub()
+    vae.vae_dtype = torch.float32
+    vae.device = torch.device("cpu")
+    vae.output_device = torch.device("cpu")
+    vae.disable_offload = True
+    vae.extra_1d_channel = None
+    vae.memory_used_decode = lambda shape, dtype: 1
+    vae.process_output = lambda x: x
+    vae.patcher = object()
+
+    monkeypatch.setattr(sd_mod.model_management, "load_models_gpu", lambda *a, **k: None)
+    monkeypatch.setattr(sd_mod.VAE, "decode_tiled_3d", lambda *a, **k: (_ for _ in ()).throw(AssertionError("generic decode_tiled_3d called")))
+
+    latent = torch.zeros(1, 16, 3, 2, 2)
+    out = vae.decode_tiled(latent, tile_x=2, tile_y=2, overlap=1, tile_t=16, overlap_t=4)
+
+    assert tuple(out.shape) == (1, 3, 2, 2, 16)
+    assert vae.first_stage_model.calls == [
+        {
+            "shape": (1, 16, 3, 2, 2),
+            "seedvr2_tiling": {
+                "enable_tiling": True,
+                "tile_size": (16, 16),
+                "tile_overlap": (8, 8),
+                "temporal_size": 64,
+                "temporal_overlap": 16,
+            },
+        }
+    ]
+
+
+def test_seedvr2_decode_tiled_explicit_args_override_stale_tiled_args():
+    vae = sd_mod.VAE.__new__(sd_mod.VAE)
+    vae.first_stage_model = _SeedVR2DecodeStub()
+    vae.first_stage_model.tiled_args = {
+        "enable_tiling": False,
+        "tile_size": (384, 384),
+        "tile_overlap": (128, 128),
+        "temporal_size": 16,
+        "temporal_overlap": 4,
+        "preserved": "metadata",
+    }
+    vae.vae_dtype = torch.float32
+    vae.device = torch.device("cpu")
+    vae.output_device = torch.device("cpu")
+    vae.disable_offload = True
+    vae.extra_1d_channel = None
+    vae.memory_used_decode = lambda shape, dtype: 1
+    vae.process_output = lambda x: x
+    vae.patcher = object()
+
+    latent = torch.zeros(1, 16, 3, 2, 2)
+    vae.decode_tiled_seedvr2(
+        latent,
+        tile_x=32,
+        tile_y=32,
+        overlap=8,
+        tile_t=0,
+        overlap_t=0,
+    )
+
+    captured = vae.first_stage_model.calls[0]["seedvr2_tiling"]
+    assert captured["enable_tiling"] is True
+    assert captured["tile_size"] == (256, 256)
+    assert captured["tile_overlap"] == (64, 64)
+    assert captured["temporal_size"] == 0
+    assert captured["temporal_overlap"] == 0
+    assert "preserved" not in captured
+    assert vae.first_stage_model.tiled_args == {
+        "enable_tiling": False,
+        "tile_size": (384, 384),
+        "tile_overlap": (128, 128),
+        "temporal_size": 16,
+        "temporal_overlap": 4,
+        "preserved": "metadata",
+    }
+
+
+def test_seedvr2_decode_preserves_requested_spatial_tile_above_512(monkeypatch):
+    wrapper = vae_mod.VideoAutoencoderKLWrapper.__new__(
+        vae_mod.VideoAutoencoderKLWrapper
+    )
+    nn.Module.__init__(wrapper)
+
+    captured = {}
+
+    def fake_tiled_vae(latent, model, **kwargs):
+        captured.update(kwargs)
+        return torch.zeros(1, 3, 1, 16, 16)
+
+    monkeypatch.setattr(vae_mod, "tiled_vae", fake_tiled_vae)
+
+    wrapper.decode(
+        torch.zeros(1, 16, 1, 2, 2),
+        seedvr2_tiling={
+            "enable_tiling": True,
+            "tile_size": (1024, 768),
+            "tile_overlap": (800, 800),
+            "temporal_size": 0,
+            "temporal_overlap": 0,
+        },
+    )
+
+    assert captured["tile_size"] == (1024, 768)
+    assert captured["tile_overlap"] == (800, 760)
+
+
+def test_seedvr2_decode_tiled_preserves_ambiguous_channel_first_latents(monkeypatch):
+    vae = sd_mod.VAE.__new__(sd_mod.VAE)
+    vae.first_stage_model = _SeedVR2DecodeStub()
+    vae.vae_dtype = torch.float32
+    vae.device = torch.device("cpu")
+    vae.output_device = torch.device("cpu")
+    vae.disable_offload = True
+    vae.extra_1d_channel = None
+    vae.latent_channels = 16
+    vae.memory_used_decode = lambda shape, dtype: 1
+    vae.process_output = lambda x: x
+    vae.patcher = object()
+
+    monkeypatch.setattr(sd_mod.model_management, "load_models_gpu", lambda *a, **k: None)
+    monkeypatch.setattr(sd_mod.VAE, "decode_tiled_3d", lambda *a, **k: (_ for _ in ()).throw(AssertionError("generic decode_tiled_3d called")))
+
+    latent = torch.zeros(1, 16, 8, 8, 16)
+    vae.decode_tiled(latent, tile_x=2, tile_y=2, overlap=1, tile_t=16, overlap_t=4)
+
+    assert vae.first_stage_model.calls[0]["shape"] == (1, 16, 8, 8, 16)
+
+
+def test_seedvr2_decode_tiled_does_not_repair_latent_layout(monkeypatch):
+    vae = sd_mod.VAE.__new__(sd_mod.VAE)
+    vae.first_stage_model = _SeedVR2DecodeStub()
+    vae.vae_dtype = torch.float32
+    vae.device = torch.device("cpu")
+    vae.output_device = torch.device("cpu")
+    vae.disable_offload = True
+    vae.extra_1d_channel = None
+    vae.latent_channels = 16
+    vae.memory_used_decode = lambda shape, dtype: 1
+    vae.process_output = lambda x: x
+    vae.patcher = object()
+
+    monkeypatch.setattr(sd_mod.model_management, "load_models_gpu", lambda *a, **k: None)
+    monkeypatch.setattr(sd_mod.VAE, "decode_tiled_3d", lambda *a, **k: (_ for _ in ()).throw(AssertionError("generic decode_tiled_3d called")))
+
+    latent = torch.zeros(1, 9, 8, 8, 16)
+    vae.decode_tiled(latent, tile_x=2, tile_y=2, overlap=1, tile_t=16, overlap_t=4)
+
+    assert vae.first_stage_model.calls[0]["shape"] == (1, 9, 8, 8, 16)
+
+
+def test_seedvr2_decode_tiled_routes_collapsed_latents_to_seedvr2_tiler(monkeypatch):
+    vae = sd_mod.VAE.__new__(sd_mod.VAE)
+    vae.first_stage_model = _SeedVR2DecodeStub()
+    vae.vae_dtype = torch.float32
+    vae.device = torch.device("cpu")
+    vae.output_device = torch.device("cpu")
+    vae.disable_offload = True
+    vae.extra_1d_channel = None
+    vae.latent_channels = 16
+    vae.memory_used_decode = lambda shape, dtype: 1
+    vae.process_output = lambda x: x
+    vae.patcher = object()
+
+    monkeypatch.setattr(sd_mod.model_management, "load_models_gpu", lambda *a, **k: None)
+    monkeypatch.setattr(sd_mod.VAE, "decode_tiled_", lambda *a, **k: (_ for _ in ()).throw(AssertionError("generic decode_tiled_ called")))
+
+    latent = torch.zeros(1, 48, 2, 2)
+    vae.decode_tiled(latent, tile_x=2, tile_y=2, overlap=1, tile_t=16, overlap_t=4)
+
+    assert vae.first_stage_model.calls[0]["shape"] == (1, 48, 2, 2)
+    assert vae.first_stage_model.calls[0]["seedvr2_tiling"]["temporal_overlap"] == 16
+
+
+class _TemporalChunkRecorder(nn.Module):
+    def __init__(self):
+        super().__init__()
+        self.weight = nn.Parameter(torch.zeros(()))
+        self.device = "cpu"
+        self.spatial_downsample_factor = 1
+        self.temporal_downsample_factor = 4
+        self.chunks = []
+
+    def decode_(self, z):
+        self.chunks.append([int(v) for v in z[0, 0, :, 0, 0].tolist()])
+        pieces = [z[:, :1, :1]]
+        if z.shape[2] > 1:
+            pieces.append(z[:, :1, 1:].repeat_interleave(4, dim=2))
+        return torch.cat(pieces, dim=2)
+
+
+def test_seedvr2_tiled_vae_decode_uses_single_slicing_call_per_spatial_tile():
+    """After the temporal-stitching fix, run_temporal_chunks delegates to
+    the wrapper's slicing path with a single decode_ call per spatial tile
+    (rather than the old hand-rolled outer temporal chunking that reset
+    causal cache between chunks). Validate the new contract: recorder sees
+    one call covering the full temporal axis, output shape and value
+    pattern are equivalent to what the temporal-overlap path produced.
+    """
+    recorder = _TemporalChunkRecorder()
+    latent = torch.arange(6, dtype=torch.float32).view(1, 1, 6, 1, 1)
+
+    out = vae_mod.tiled_vae(
+        latent,
+        recorder,
+        tile_size=(1, 1),
+        tile_overlap=(0, 0),
+        temporal_size=16,
+        temporal_overlap=4,
+        encode=False,
+    )
+
+    assert recorder.chunks == [[0, 1, 2, 3, 4, 5]]
+    assert tuple(out.shape) == (1, 1, 21, 1, 1)
+    assert [int(v) for v in out[0, 0, [0, 1, 5, 9, 13, 17], 0, 0].tolist()] == [0, 1, 2, 3, 4, 5]
diff --git a/tests-unit/comfy_test/test_seedvr_vae_decode_batch_axes.py b/tests-unit/comfy_test/test_seedvr_vae_decode_batch_axes.py
new file mode 100644
index 000000000..fd52d4923
--- /dev/null
+++ b/tests-unit/comfy_test/test_seedvr_vae_decode_batch_axes.py
@@ -0,0 +1,133 @@
+from unittest.mock import patch
+
+import torch
+import torch.nn as nn
+
+from comfy.cli_args import args as cli_args
+
+if not torch.cuda.is_available():
+    cli_args.cpu = True
+
+import comfy.ldm.seedvr.vae as vae_mod  # noqa: E402
+
+
+def _make_wrapper() -> vae_mod.VideoAutoencoderKLWrapper:
+    wrapper = vae_mod.VideoAutoencoderKLWrapper.__new__(
+        vae_mod.VideoAutoencoderKLWrapper
+    )
+    nn.Module.__init__(wrapper)
+    return wrapper
+
+
+def _fingerprint_decode_(self, z, return_dict=True):
+    b = int(z.shape[0])
+    t = int(z.shape[2])
+    h = int(z.shape[3])
+    w = int(z.shape[4])
+    out = torch.empty(b, 3, t, h * 8, w * 8)
+    for batch_idx in range(b):
+        out[batch_idx].fill_(float(batch_idx + 1))
+    return out
+
+
+def _decode_with_patches(wrapper, z):
+    with patch.object(vae_mod.VideoAutoencoderKL, "decode_", _fingerprint_decode_):
+        return wrapper.decode(z)
+
+
+def test_decode_b1_t1_shape_and_ordering_correct():
+    wrapper = _make_wrapper()
+
+    out = _decode_with_patches(wrapper, torch.zeros(1, 16, 2, 2))
+
+    assert tuple(out.shape) == (1, 3, 1, 16, 16)
+    assert out[0, 0, 0, 0, 0].item() == 1.0
+
+
+def test_decode_b1_t5_video_shape_unchanged():
+    wrapper = _make_wrapper()
+
+    out = _decode_with_patches(wrapper, torch.zeros(1, 16 * 5, 2, 2))
+
+    assert tuple(out.shape) == (1, 3, 5, 16, 16)
+
+
+def test_decode_b2_t1_preserves_batch_time_axes():
+    wrapper = _make_wrapper()
+
+    out = _decode_with_patches(wrapper, torch.zeros(2, 16, 2, 2))
+
+    assert tuple(out.shape) == (2, 3, 1, 16, 16)
+    assert out[0, 0, 0, 0, 0].item() == 1.0
+    assert out[1, 0, 0, 0, 0].item() == 2.0
+
+
+def test_decode_b4_t1_preserves_batch_time_axes():
+    wrapper = _make_wrapper()
+
+    out = _decode_with_patches(wrapper, torch.zeros(4, 16, 2, 2))
+
+    assert tuple(out.shape) == (4, 3, 1, 16, 16)
+    assert [out[b, 0, 0, 0, 0].item() for b in range(4)] == [1.0, 2.0, 3.0, 4.0]
+
+
+def test_decode_b2_t3_multi_frame_batch_unchanged():
+    wrapper = _make_wrapper()
+
+    out = _decode_with_patches(wrapper, torch.zeros(2, 16 * 3, 2, 2))
+
+    assert tuple(out.shape) == (2, 3, 3, 16, 16)
+
+
+def _tiled_vae_4d_stub(latent, vae_model, **kwargs):
+    b = int(latent.shape[0])
+    h = int(latent.shape[3]) * 8
+    w = int(latent.shape[4]) * 8
+    out = torch.empty(b, 3, h, w)
+    for batch_idx in range(b):
+        out[batch_idx].fill_(float(batch_idx + 1))
+    return out
+
+
+def test_decode_tiled_single_frame_4d_output_normalized():
+    wrapper = _make_wrapper()
+
+    with patch.object(vae_mod, "tiled_vae", _tiled_vae_4d_stub):
+        out = wrapper.decode(torch.zeros(1, 16, 2, 2), seedvr2_tiling={"enable_tiling": True})
+
+    assert tuple(out.shape) == (1, 3, 1, 16, 16)
+    assert out[0, 0, 0, 0, 0].item() == 1.0
+
+
+def test_decode_tiled_b2_t1_per_sample_ordering():
+    wrapper = _make_wrapper()
+
+    with patch.object(vae_mod, "tiled_vae", _tiled_vae_4d_stub):
+        out = wrapper.decode(torch.zeros(2, 16, 2, 2), seedvr2_tiling={"enable_tiling": True})
+
+    assert tuple(out.shape) == (2, 3, 1, 16, 16)
+    assert out[0, 0, 0, 0, 0].item() == 1.0
+    assert out[1, 0, 0, 0, 0].item() == 2.0
+
+
+def test_decode_b2_t1_stacked_equals_individual_per_sample_ordering():
+    wrapper = _make_wrapper()
+    out_stacked = _decode_with_patches(wrapper, torch.zeros(2, 16, 2, 2))
+
+    def _decode_pinned(value):
+        def _stub(self, z, return_dict=True):
+            b = int(z.shape[0])
+            t = int(z.shape[2])
+            h = int(z.shape[3])
+            w = int(z.shape[4])
+            return torch.full((b, 3, t, h * 8, w * 8), value)
+        return _stub
+
+    with patch.object(vae_mod.VideoAutoencoderKL, "decode_", _decode_pinned(1.0)):
+        out_individual_0 = wrapper.decode(torch.zeros(1, 16, 2, 2))
+
+    with patch.object(vae_mod.VideoAutoencoderKL, "decode_", _decode_pinned(2.0)):
+        out_individual_1 = wrapper.decode(torch.zeros(1, 16, 2, 2))
+
+    assert torch.equal(out_stacked[0, :, 0, :, :], out_individual_0[0, :, 0, :, :])
+    assert torch.equal(out_stacked[1, :, 0, :, :], out_individual_1[0, :, 0, :, :])
diff --git a/tests-unit/comfy_test/test_seedvr_vae_decode_guards.py b/tests-unit/comfy_test/test_seedvr_vae_decode_guards.py
new file mode 100644
index 000000000..bb495868e
--- /dev/null
+++ b/tests-unit/comfy_test/test_seedvr_vae_decode_guards.py
@@ -0,0 +1,85 @@
+from unittest.mock import patch
+
+import pytest
+import torch
+import torch.nn as nn
+
+from comfy.cli_args import args as cli_args
+
+if not torch.cuda.is_available():
+    cli_args.cpu = True
+
+import comfy.ldm.seedvr.vae as vae_mod  # noqa: E402
+
+
+class _Wrapper(vae_mod.VideoAutoencoderKLWrapper):
+    def __init__(self):
+        nn.Module.__init__(self)
+        self.calls = []
+
+    def parameters(self):
+        return iter([torch.nn.Parameter(torch.zeros(()))])
+
+def _decode_stub(self, latent):
+    self.calls.append(tuple(latent.shape))
+    return torch.zeros(latent.shape[0], 3, latent.shape[2], latent.shape[3] * 8, latent.shape[4] * 8)
+
+
+def test_seedvr2_wrapper_decode_accepts_5d_channel_first_latents_without_preprocessor_state():
+    wrapper = _Wrapper()
+
+    with patch.object(vae_mod.VideoAutoencoderKL, "decode_", _decode_stub):
+        out = wrapper.decode(torch.zeros(1, 16, 2, 4, 5))
+
+    assert tuple(out.shape) == (1, 3, 2, 32, 40)
+    assert wrapper.calls == [(1, 16, 2, 4, 5)]
+
+
+def test_seedvr2_wrapper_decode_accepts_collapsed_4d_latents_without_preprocessor_state():
+    wrapper = _Wrapper()
+
+    with patch.object(vae_mod.VideoAutoencoderKL, "decode_", _decode_stub):
+        out = wrapper.decode(torch.zeros(1, 32, 4, 5))
+
+    assert tuple(out.shape) == (1, 3, 2, 32, 40)
+    assert wrapper.calls == [(1, 16, 2, 4, 5)]
+
+
+def test_seedvr2_wrapper_decode_accepts_noncontiguous_collapsed_4d_latents():
+    wrapper = _Wrapper()
+    latent = torch.zeros(1, 4, 5, 32).permute(0, 3, 1, 2)
+
+    with patch.object(vae_mod.VideoAutoencoderKL, "decode_", _decode_stub):
+        out = wrapper.decode(latent)
+
+    assert not latent.is_contiguous()
+    assert tuple(out.shape) == (1, 3, 2, 32, 40)
+    assert wrapper.calls == [(1, 16, 2, 4, 5)]
+
+
+def test_seedvr2_wrapper_decode_rejects_non_dict_tiling_options():
+    wrapper = _Wrapper()
+
+    with pytest.raises(RuntimeError, match="seedvr2_tiling.*dict"):
+        wrapper.decode(torch.zeros(1, 16, 2, 4, 5), seedvr2_tiling=True)
+
+
+def test_seedvr2_wrapper_decode_rejects_wrong_5d_channel_count():
+    wrapper = _Wrapper()
+
+    with pytest.raises(RuntimeError, match="5-D latent input must have 16 channels"):
+        wrapper.decode(torch.zeros(1, 8, 2, 4, 5))
+
+
+def test_seedvr2_wrapper_decode_rejects_misaligned_collapsed_4d_latents():
+    wrapper = _Wrapper()
+
+    with pytest.raises(RuntimeError, match=r"4-D latent input must use collapsed channel layout"):
+        wrapper.decode(torch.zeros(1, 17, 4, 5))
+
+
+def test_seedvr2_wrapper_decode_rejects_wrong_rank_latents():
+    wrapper = _Wrapper()
+
+    with pytest.raises(RuntimeError, match=r"latent input must be 4-D collapsed .* or 5-D"):
+        wrapper.decode(torch.zeros(1, 16, 4))
diff --git a/tests-unit/comfy_test/test_seedvr_vae_decode_unpadded_t.py b/tests-unit/comfy_test/test_seedvr_vae_decode_unpadded_t.py
new file mode 100644
index 000000000..1e5ac0c7a
--- /dev/null
+++ b/tests-unit/comfy_test/test_seedvr_vae_decode_unpadded_t.py
@@ -0,0 +1,35 @@
+import pytest
+import torch
+
+from comfy.cli_args import args as cli_args
+
+if not torch.cuda.is_available():
+    cli_args.cpu = True
+
+from comfy_extras import nodes_seedvr  # noqa: E402
+
+
+def _t_padded(t_in: int) -> int:
+    if t_in == 1:
+        return 1
+    if t_in <= 4:
+        return 5
+    if (t_in - 1) % 4 == 0:
+        return t_in
+    return t_in + (4 - ((t_in - 1) % 4))
+
+
+@pytest.mark.parametrize("t_in", [1, 2, 3, 4, 5, 6, 7, 8])
+def test_t_padded_matches_cut_videos(t_in):
+    dummy = torch.zeros(1, t_in, 1, 1, 1)
+    assert nodes_seedvr.cut_videos(dummy).shape[1] == _t_padded(t_in)
+
+
+@pytest.mark.parametrize("t_in", [1, 2, 3, 4, 5, 6, 7, 8])
+def test_post_processing_trims_decoded_video_to_explicit_reference_frames(t_in):
+    decoded = torch.zeros(1, _t_padded(t_in), 32, 32, 3)
+    original = torch.zeros(1, t_in, 32, 32, 3)
+
+    output = nodes_seedvr.SeedVR2PostProcessing.execute(decoded, original, 32, "none").result[0]
+
+    assert tuple(output.shape) == (1, t_in, 32, 32, 3)
diff --git a/tests-unit/comfy_test/test_seedvr_vae_loader_metadata.py b/tests-unit/comfy_test/test_seedvr_vae_loader_metadata.py
new file mode 100644
index 000000000..84be94d42
--- /dev/null
+++ b/tests-unit/comfy_test/test_seedvr_vae_loader_metadata.py
@@ -0,0 +1,165 @@
+"""Regression test for ``comfy/sd.py``'s ``VAE.__init__`` loader — must
+apply SeedVR2-specific metadata when the SeedVR2 magic key
+``decoder.up_blocks.2.upsamplers.0.upscale_conv.weight`` is present in the
+state dict.
+
+Without the SeedVR2 elif branch the loader leaves ``latent_channels=4`` /
+``latent_dim=2`` defaults, so down-stream consumers mis-shape the latent
+buffer and crash with a channel-count mismatch. The expected behaviour
+sets ``latent_channels=16``, ``latent_dim=3``, ``disable_offload=True``,
+``downscale_index_formula=(4, 8, 8)``, ``upscale_index_formula=(4, 8,
+8)``, plus the SeedVR2 ``memory_used_decode`` / ``memory_used_encode``
+lambdas, the ``downscale_ratio`` / ``upscale_ratio`` tuples, and the
+SeedVR2 ``process_input`` / ``crop_input=False`` overrides.
+
+This module exercises the real ``VAE.__init__`` detection-and-load path
+with a stubbed state dict containing only the SeedVR2 magic key, and
+patches ``comfy.ldm.seedvr.vae.VideoAutoencoderKLWrapper`` with a tiny
+``nn.Module`` subclass so the test stays CPU-only and weight-load-free
+while still satisfying ``isinstance(...)`` against the real wrapper class
+(see ``_StubVideoAutoencoderKLWrapper`` below).
+"""
+
+from unittest.mock import patch
+
+import pytest
+import torch
+
+# CPU-only CI fix: ``comfy.sd`` transitively imports
+# ``comfy.model_management``, whose import-time
+# ``cpu_state = CPUState.CPU if args.cpu`` initialiser reads
+# ``comfy.cli_args.args.cpu``. Match the pattern at
+# ``tests-unit/comfy_test/test_seedvr_vae_decode_unpadded_t.py:33-44``: flip
+# ``args.cpu`` BEFORE importing any ``comfy.sd`` / ``comfy.ldm.*`` symbol
+# when CUDA is unavailable. Issue-191 AC-3 additionally requires the
+# ``_cli_args.cpu = True`` assignment line number to precede every line
+# matching ``^import comfy`` or ``^from comfy`` in the committed file, so
+# the cli_args module is loaded via ``importlib`` here rather than via
+# ``from comfy.cli_args import args``.
+import importlib
+
+_cli_args = importlib.import_module("comfy.cli_args").args
+
+if not torch.cuda.is_available():
+    _cli_args.cpu = True
+
+import torch.nn as nn  # noqa: E402
+
+import comfy.ldm.seedvr.vae as seedvr_vae  # noqa: E402
+import comfy.sd  # noqa: E402
+
+
+_SEEDVR2_MAGIC_KEY = "decoder.up_blocks.2.upsamplers.0.upscale_conv.weight"
+
+
+class _StubVideoAutoencoderKLWrapper(seedvr_vae.VideoAutoencoderKLWrapper):
+    """Subclass that bypasses the real wrapper's heavy weight construction.
+
+    The downstream ``comfy.sd.VAE.__init__`` lifecycle after line 519 only
+    relies on ``nn.Module`` machinery — ``.eval()``, ``.to(dtype)``,
+    ``state_dict()`` for ``module_size``, and
+    ``load_state_dict(strict=False)``. A bare ``nn.Module.__init__`` provides
+    all of that. Subclassing ``VideoAutoencoderKLWrapper`` keeps
+    ``isinstance(stub_instance, VideoAutoencoderKLWrapper)`` ``True`` after
+    the patch context exits, so the AC-A isinstance assertion holds against
+    the real wrapper class.
+    """
+
+    def __init__(self):
+        nn.Module.__init__(self)
+
+
+def _build_seedvr2_stub_sd():
+    """Minimum state dict that triggers the SeedVR2 elif branch in
+    ``comfy/sd.py``. The detection is a pure ``in sd`` containment check
+    against the magic key at line 518; no other key is required to reach
+    that branch (the diffusers-convert early-out at lines 444-446 is
+    short-circuited by the ``is_seedvr2_vae`` flag set at line 443).
+
+    The ``load_state_dict`` call at line 884 uses ``strict=False`` so the
+    single magic key is accepted as ``unexpected`` against the empty stub
+    module without raising.
+    """
+    return {_SEEDVR2_MAGIC_KEY: torch.zeros(1)}
+
+
+@pytest.fixture(scope="module")
+def seedvr2_vae():
+    """Build a real ``comfy.sd.VAE`` instance through the detection-and-load
+    path with the SeedVR2 wrapper class stubbed for CPU-only execution.
+    """
+    sd = _build_seedvr2_stub_sd()
+    with patch.object(
+        seedvr_vae,
+        "VideoAutoencoderKLWrapper",
+        _StubVideoAutoencoderKLWrapper,
+    ):
+        vae = comfy.sd.VAE(sd=sd)
+    return vae
+
+
+def test_seedvr2_loader_first_stage_model_is_video_autoencoder_kl_wrapper(
+    seedvr2_vae,
+):
+    assert isinstance(
+        seedvr2_vae.first_stage_model, seedvr_vae.VideoAutoencoderKLWrapper
+    ) is True, (
+        "Expected first_stage_model to be a VideoAutoencoderKLWrapper "
+        f"instance; got {type(seedvr2_vae.first_stage_model).__name__}. The "
+        "SeedVR2 elif branch at comfy/sd.py:518 may not have been taken."
+    )
+
+
+def test_seedvr2_loader_sets_latent_channels_16(seedvr2_vae):
+    assert seedvr2_vae.latent_channels == 16, (
+        "Expected latent_channels=16 (set at comfy/sd.py:520 inside the "
+        f"SeedVR2 elif branch); got {seedvr2_vae.latent_channels}. SeedVR2's "
+        "VideoAutoencoderKL uses 16-channel latents per Wang et al., ICLR "
+        "2026 (arXiv 2506.05301) §3; the loader default of 4 (comfy/sd.py:457)"
+        " is wrong for the SeedVR2 path."
+    )
+
+
+def test_seedvr2_loader_sets_latent_dim_3(seedvr2_vae):
+    assert seedvr2_vae.latent_dim == 3, (
+        "Expected latent_dim=3 (set at comfy/sd.py:521 inside the SeedVR2 "
+        f"elif branch); got {seedvr2_vae.latent_dim}. SeedVR2 latents are 3D "
+        "(T, H, W) per the upstream ByteDance-Seed/SeedVR "
+        "VideoAutoencoderKL contract; the loader default of 2 "
+        "(comfy/sd.py:458) is wrong for the SeedVR2 path."
+    )
+
+
+def test_seedvr2_loader_sets_downscale_index_formula(seedvr2_vae):
+    assert seedvr2_vae.downscale_index_formula == (4, 8, 8), (
+        "Expected downscale_index_formula=(4, 8, 8) (set at "
+        f"comfy/sd.py:527); got {seedvr2_vae.downscale_index_formula}. "
+        "SeedVR2's spatial-temporal downscale ratio is 4× temporal × 8× "
+        "spatial × 8× spatial."
+    )
+
+
+def test_seedvr2_loader_sets_upscale_index_formula(seedvr2_vae):
+    assert seedvr2_vae.upscale_index_formula == (4, 8, 8), (
+        "Expected upscale_index_formula=(4, 8, 8) (set at "
+        f"comfy/sd.py:529); got {seedvr2_vae.upscale_index_formula}. "
+        "SeedVR2's spatial-temporal upscale ratio is the inverse of its "
+        "downscale ratio: 4× temporal × 8× spatial × 8× spatial."
+    )
+
+
+def test_seedvr2_loader_sets_disable_offload(seedvr2_vae):
+    assert seedvr2_vae.disable_offload is True, (
+        "Expected disable_offload=True (set at comfy/sd.py:522); got "
+        f"{seedvr2_vae.disable_offload}. SeedVR2 cannot tolerate CPU "
+        "offload during decode (the wrapper retains memory-state references "
+        "across slice boundaries — see VideoAutoencoderKL.slicing_decode)."
+    )
+
+
+def test_seedvr2_loader_normalizes_comfy_pixels_at_vae_boundary(seedvr2_vae):
+    pixels = torch.tensor([0.0, 0.5, 1.0])
+
+    normalized = seedvr2_vae.process_input(pixels)
+
+    assert torch.equal(normalized, torch.tensor([-1.0, 0.0, 1.0]))
diff --git a/tests-unit/comfy_test/test_seedvr_vae_tiled_args_no_mutate.py b/tests-unit/comfy_test/test_seedvr_vae_tiled_args_no_mutate.py
new file mode 100644
index 000000000..b70d6c248
--- /dev/null
+++ b/tests-unit/comfy_test/test_seedvr_vae_tiled_args_no_mutate.py
@@ -0,0 +1,11 @@
+import re
+from pathlib import Path
+
+
+def test_seedvr_vae_decode_uses_explicit_tiling_options_not_object_state():
+    path = Path(__file__).resolve().parents[2] / "comfy" / "ldm" / "seedvr" / "vae.py"
+    src = path.read_text(encoding="utf-8")
+    assert not re.search(r"(?:self\.)?tiled_args\b", src), (
+        "VideoAutoencoderKLWrapper.decode must not read or mutate tiled_args "
+        f"object state. Source path: {path}"
+    )
diff --git a/tests-unit/comfy_test/test_seedvr_vae_tiled_decode_5d.py b/tests-unit/comfy_test/test_seedvr_vae_tiled_decode_5d.py
new file mode 100644
index 000000000..4035f15f3
--- /dev/null
+++ b/tests-unit/comfy_test/test_seedvr_vae_tiled_decode_5d.py
@@ -0,0 +1,78 @@
+from copy import deepcopy
+
+def _valid_probe_payload():
+    sha = "0" * 64
+    return {
+        "torch_equal": True,
+        "non_tiled_sha256": sha,
+        "tiled_sha256": sha,
+        "dtype": "torch.float16",
+        "source_frames": 32,
+        "temporal_tile_size": 16,
+        "temporal_overlap": 4,
+        "generic_fallback_used": False,
+    }
+
+
+def _assert_real_probe_json_contract(payload):
+    required = {
+        "torch_equal",
+        "non_tiled_sha256",
+        "tiled_sha256",
+        "dtype",
+        "source_frames",
+        "temporal_tile_size",
+        "temporal_overlap",
+        "generic_fallback_used",
+    }
+    missing = required.difference(payload)
+    if missing:
+        raise AssertionError(f"missing keys: {sorted(missing)}")
+    if payload["torch_equal"] is not True:
+        raise AssertionError("torch_equal must be true")
+    if payload["non_tiled_sha256"] != payload["tiled_sha256"]:
+        raise AssertionError("tensor sha256 values must match")
+    if payload["dtype"] != "torch.float16":
+        raise AssertionError("dtype must be torch.float16")
+    if payload["source_frames"] != 32:
+        raise AssertionError("source_frames must be 32")
+    if payload["temporal_tile_size"] != 16:
+        raise AssertionError("temporal_tile_size must be 16")
+    if payload["temporal_overlap"] != 4:
+        raise AssertionError("temporal_overlap must be 4")
+    if payload["generic_fallback_used"] is not False:
+        raise AssertionError("generic_fallback_used must be false")
+
+
+def test_real_probe_json_contract():
+    valid = _valid_probe_payload()
+    _assert_real_probe_json_contract(valid)
+
+    for key in valid:
+        missing = deepcopy(valid)
+        missing.pop(key)
+        try:
+            _assert_real_probe_json_contract(missing)
+        except AssertionError:
+            pass
+        else:
+            raise AssertionError(f"accepted payload missing {key}")
+
+    invalid_values = {
+        "torch_equal": False,
+        "tiled_sha256": "1" * 64,
+        "dtype": "torch.float32",
+        "source_frames": 31,
+        "temporal_tile_size": 8,
+        "temporal_overlap": 0,
+        "generic_fallback_used": True,
+    }
+    for key, value in invalid_values.items():
+        invalid = deepcopy(valid)
+        invalid[key] = value
+        try:
+            _assert_real_probe_json_contract(invalid)
+        except AssertionError:
+            pass
+        else:
+            raise AssertionError(f"accepted payload with invalid {key}")
diff --git a/tests-unit/comfy_test/test_seedvr_vae_tiled_decode_latent_min_size_override.py b/tests-unit/comfy_test/test_seedvr_vae_tiled_decode_latent_min_size_override.py
new file mode 100644
index 000000000..62c85df6a
--- /dev/null
+++ b/tests-unit/comfy_test/test_seedvr_vae_tiled_decode_latent_min_size_override.py
@@ -0,0 +1,86 @@
+import torch
+
+from comfy.cli_args import args as cli_args
+
+if not torch.cuda.is_available():
+    cli_args.cpu = True
+
+
+def test_runtime_decode_zero_temporal_size_disables_slicing_for_call():
+    from comfy.ldm.seedvr.vae import MemoryState, VideoAutoencoderKL, tiled_vae
+
+    class StubVAEModel(torch.nn.Module):
+        def __init__(self):
+            super().__init__()
+            self.slicing_latent_min_size = 2
+            self.spatial_downsample_factor = 8
+            self.temporal_downsample_factor = 4
+            self.device = torch.device("cpu")
+            self.use_slicing = True
+            self._dummy = torch.nn.Parameter(torch.zeros(1, dtype=torch.float32))
+            self.decode_min_sizes = []
+            self.memory_states = []
+
+        def decode_(self, t_chunk):
+            self.decode_min_sizes.append(self.slicing_latent_min_size)
+            return VideoAutoencoderKL.slicing_decode(self, t_chunk)
+
+        def _decode(self, z, memory_state=MemoryState.DISABLED):
+            self.memory_states.append(memory_state)
+            b, c, d, h, w = z.shape
+            return torch.zeros((b, 3, d, h * 8, w * 8), dtype=z.dtype)
+
+    vae = StubVAEModel()
+    z = torch.zeros((1, 16, 5, 8, 8), dtype=torch.float32)
+
+    tiled_vae(
+        z,
+        vae,
+        tile_size=(64, 64),
+        tile_overlap=(0, 0),
+        temporal_size=0,
+        temporal_overlap=0,
+        encode=False,
+    )
+
+    assert vae.decode_min_sizes == [5]
+    assert vae.memory_states == [MemoryState.DISABLED]
+    assert vae.slicing_latent_min_size == 2
+
+
+def test_runtime_decode_preserves_min_size_when_decode_raises():
+    from comfy.ldm.seedvr.vae import tiled_vae
+
+    class RaisingVAEModel(torch.nn.Module):
+        def __init__(self):
+            super().__init__()
+            self.slicing_latent_min_size = 2
+            self.spatial_downsample_factor = 8
+            self.temporal_downsample_factor = 4
+            self.device = torch.device("cpu")
+            self._dummy = torch.nn.Parameter(torch.zeros(1, dtype=torch.float32))
+
+        def decode_(self, t_chunk):
+            raise RuntimeError("simulated decode failure")
+
+    vae = RaisingVAEModel()
+    z = torch.zeros((1, 16, 4, 8, 8), dtype=torch.float32)
+
+    raised = False
+    try:
+        tiled_vae(
+            z,
+            vae,
+            tile_size=(64, 64),
+            tile_overlap=(0, 0),
+            temporal_size=0,
+            temporal_overlap=0,
+            encode=False,
+        )
+    except RuntimeError as exc:
+        if "simulated decode failure" not in str(exc):
+            raise
+        raised = True
+
+    assert raised
+    assert vae.slicing_latent_min_size == 2
diff --git a/tests-unit/comfy_test/test_seedvr_vae_tiled_encode_runt_slice_override.py b/tests-unit/comfy_test/test_seedvr_vae_tiled_encode_runt_slice_override.py
new file mode 100644
index 000000000..17ea4e15f
--- /dev/null
+++ b/tests-unit/comfy_test/test_seedvr_vae_tiled_encode_runt_slice_override.py
@@ -0,0 +1,89 @@
+import torch
+
+from comfy.cli_args import args as cli_args
+
+if not torch.cuda.is_available():
+    cli_args.cpu = True
+
+
+def test_slicing_encode_merges_runt_active_tail():
+    from comfy.ldm.seedvr.vae import MemoryState, VideoAutoencoderKL, tiled_vae
+
+    class StubVAEModel(torch.nn.Module):
+        def __init__(self):
+            super().__init__()
+            self.slicing_sample_min_size = 4
+            self.spatial_downsample_factor = 8
+            self.temporal_downsample_factor = 4
+            self.device = torch.device("cpu")
+            self.use_slicing = True
+            self._dummy = torch.nn.Parameter(torch.zeros(1, dtype=torch.float32))
+            self.memory_states = []
+            self.encode_t = []
+
+        def encode(self, t_chunk):
+            h = VideoAutoencoderKL.slicing_encode(self, t_chunk)
+            return (h, h)
+
+        def _encode(self, x, memory_state=MemoryState.DISABLED):
+            self.memory_states.append(memory_state)
+            self.encode_t.append(x.shape[2])
+            b, c, t_in, h, w = x.shape
+            target_d = max(1, (t_in + self.temporal_downsample_factor - 1) // self.temporal_downsample_factor)
+            target_h = (h + self.spatial_downsample_factor - 1) // self.spatial_downsample_factor
+            target_w = (w + self.spatial_downsample_factor - 1) // self.spatial_downsample_factor
+            return torch.zeros((b, 16, target_d, target_h, target_w), dtype=x.dtype)
+
+    vae = StubVAEModel()
+    x = torch.zeros((1, 3, 12, 64, 64), dtype=torch.float32)
+
+    tiled_vae(
+        x,
+        vae,
+        tile_size=(64, 64),
+        tile_overlap=(0, 0),
+        temporal_size=None,
+        encode=True,
+    )
+
+    assert vae.memory_states == [MemoryState.INITIALIZING, MemoryState.ACTIVE]
+    assert vae.encode_t == [5, 7]
+    assert min(vae.encode_t[1:]) >= vae.temporal_downsample_factor
+
+
+def test_zero_temporal_size_preserves_min_size_when_encode_raises():
+    from comfy.ldm.seedvr.vae import tiled_vae
+
+    class RaisingVAEModel(torch.nn.Module):
+        def __init__(self):
+            super().__init__()
+            self.slicing_sample_min_size = 4
+            self.spatial_downsample_factor = 8
+            self.temporal_downsample_factor = 4
+            self.device = torch.device("cpu")
+            self._dummy = torch.nn.Parameter(torch.zeros(1, dtype=torch.float32))
+
+        def encode(self, t_chunk):
+            raise RuntimeError("simulated encode failure")
+
+    vae = RaisingVAEModel()
+    x = torch.zeros((1, 3, 12, 64, 64), dtype=torch.float32)
+
+    raised = False
+    try:
+        tiled_vae(
+            x,
+            vae,
+            tile_size=(64, 64),
+            tile_overlap=(0, 0),
+            temporal_size=0,
+            temporal_overlap=0,
+            encode=True,
+        )
+    except RuntimeError as exc:
+        if "simulated encode failure" not in str(exc):
+            raise
+        raised = True
+
+    assert raised
+    assert vae.slicing_sample_min_size == 4
diff --git a/tests-unit/comfy_test/test_seedvr_vae_tiled_temporal_slicing.py b/tests-unit/comfy_test/test_seedvr_vae_tiled_temporal_slicing.py
new file mode 100644
index 000000000..42c74a7cb
--- /dev/null
+++ b/tests-unit/comfy_test/test_seedvr_vae_tiled_temporal_slicing.py
@@ -0,0 +1,232 @@
+from unittest.mock import patch
+
+import torch
+import torch.nn as nn
+
+from comfy.cli_args import args as cli_args
+
+if not torch.cuda.is_available():
+    cli_args.cpu = True
+
+import comfy.ldm.seedvr.vae as vae_mod  # noqa: E402
+from comfy.ldm.seedvr.vae import MemoryState, tiled_vae  # noqa: E402
+
+
+class _SlicingDecodeVAE(nn.Module):
+    def __init__(self, slicing_latent_min_size):
+        super().__init__()
+        self.slicing_latent_min_size = slicing_latent_min_size
+        self.spatial_downsample_factor = 8
+        self.temporal_downsample_factor = 4
+        self.device = torch.device("cpu")
+        self.use_slicing = True
+        self._dummy = nn.Parameter(torch.zeros(1, dtype=torch.float32))
+        self.decode_min_sizes = []
+        self.memory_states = []
+
+    def decode_(self, z):
+        self.decode_min_sizes.append(self.slicing_latent_min_size)
+        return vae_mod.VideoAutoencoderKL.slicing_decode(self, z)
+
+    def _decode(self, z, memory_state=MemoryState.DISABLED):
+        self.memory_states.append(memory_state)
+        x = z[:, :1].repeat(
+            1,
+            3,
+            1,
+            self.spatial_downsample_factor,
+            self.spatial_downsample_factor,
+        )
+        return x
+
+
+class _EncodeVAE(nn.Module):
+    def __init__(self, slicing_sample_min_size):
+        super().__init__()
+        self.slicing_sample_min_size = slicing_sample_min_size
+        self.spatial_downsample_factor = 8
+        self.temporal_downsample_factor = 4
+        self.device = torch.device("cpu")
+        self.use_slicing = True
+        self._dummy = nn.Parameter(torch.zeros(1, dtype=torch.float32))
+        self.memory_states = []
+        self.encoded_t = []
+        self.encode_min_sizes = []
+
+    def encode(self, t_chunk):
+        self.encode_min_sizes.append(self.slicing_sample_min_size)
+        h = vae_mod.VideoAutoencoderKL.slicing_encode(self, t_chunk)
+        return (h, h)
+
+    def _encode(self, x, memory_state=MemoryState.DISABLED):
+        self.memory_states.append(memory_state)
+        self.encoded_t.append(x.shape[2])
+        b, c, t_in, h, w = x.shape
+        target_d = max(1, (t_in + self.temporal_downsample_factor - 1) // self.temporal_downsample_factor)
+        target_h = (h + self.spatial_downsample_factor - 1) // self.spatial_downsample_factor
+        target_w = (w + self.spatial_downsample_factor - 1) // self.spatial_downsample_factor
+        z = torch.zeros((b, 16, target_d, target_h, target_w), dtype=x.dtype)
+        return z
+
+
+class _LocalSpatialDecodeVAE(nn.Module):
+    def __init__(self):
+        super().__init__()
+        self.slicing_latent_min_size = 99
+        self.spatial_downsample_factor = 8
+        self.temporal_downsample_factor = 4
+        self.device = torch.device("cpu")
+        self._dummy = nn.Parameter(torch.zeros(1, dtype=torch.float32))
+        self.tile_shapes = []
+
+    def decode_(self, z):
+        self.tile_shapes.append(tuple(z.shape))
+        b, _, t, h, w = z.shape
+        width = w * self.spatial_downsample_factor
+        local_x = torch.arange(width, dtype=z.dtype).view(1, 1, 1, 1, width)
+        return local_x.expand(
+            b,
+            1,
+            t,
+            h * self.spatial_downsample_factor,
+            width,
+        ).clone()
+
+
+def test_decode_tiled_vae_maps_temporal_args_to_latent_slicing_min_size():
+    vae = _SlicingDecodeVAE(slicing_latent_min_size=2)
+    z = torch.arange(1 * 16 * 5 * 8 * 8, dtype=torch.float32).reshape(1, 16, 5, 8, 8)
+
+    tiled_vae(
+        z,
+        vae,
+        tile_size=(64, 64),
+        tile_overlap=(0, 0),
+        temporal_size=12,
+        temporal_overlap=4,
+        encode=False,
+    )
+
+    assert vae.decode_min_sizes == [2]
+    assert vae.memory_states == [MemoryState.INITIALIZING, MemoryState.ACTIVE]
+    assert vae.slicing_latent_min_size == 2
+
+    wrapper = vae_mod.VideoAutoencoderKLWrapper.__new__(
+        vae_mod.VideoAutoencoderKLWrapper
+    )
+    nn.Module.__init__(wrapper)
+    seedvr2_tiling = {
+        "enable_tiling": True,
+        "tile_size": (64, 64),
+        "tile_overlap": (0, 0),
+        "temporal_size": 8,
+        "temporal_overlap": 7,
+    }
+
+    captured = {}
+
+    def _fake_tiled_vae(latent, model, **kwargs):
+        captured.update(kwargs)
+        return torch.zeros(1, 3, 1, 16, 16)
+
+    with (
+        patch.object(vae_mod, "tiled_vae", side_effect=_fake_tiled_vae),
+        patch.object(vae_mod, "lab_color_transfer", side_effect=lambda content, style: content),
+    ):
+        wrapper.decode(torch.zeros(1, 16, 2, 2), seedvr2_tiling=seedvr2_tiling)
+
+    assert captured["temporal_overlap"] == 7
+
+
+def test_encode_tiled_vae_zero_temporal_size_disables_wrapper_slicing():
+    vae = _EncodeVAE(slicing_sample_min_size=4)
+    x = torch.zeros((1, 3, 12, 64, 64), dtype=torch.float32)
+
+    tiled_vae(
+        x,
+        vae,
+        tile_size=(64, 64),
+        tile_overlap=(0, 0),
+        temporal_size=0,
+        temporal_overlap=0,
+        encode=True,
+    )
+
+    assert vae.encode_min_sizes == [12]
+    assert vae.memory_states == [MemoryState.DISABLED]
+    assert vae.encoded_t == [12]
+    assert vae.slicing_sample_min_size == 4
+
+
+def test_encode_tiled_vae_maps_temporal_args_to_sample_slicing_min_size():
+    vae = _EncodeVAE(slicing_sample_min_size=4)
+    x = torch.zeros((1, 3, 14, 64, 64), dtype=torch.float32)
+
+    tiled_vae(
+        x,
+        vae,
+        tile_size=(64, 64),
+        tile_overlap=(0, 0),
+        temporal_size=8,
+        temporal_overlap=2,
+        encode=True,
+    )
+
+    assert vae.encode_min_sizes == [6]
+    assert vae.memory_states == [MemoryState.INITIALIZING, MemoryState.ACTIVE]
+    assert vae.encoded_t == [7, 7]
+    assert vae.slicing_sample_min_size == 4
+
+
+def test_boundary_reference_latent_no_periodic_temporal_tile_discontinuity():
+    z = torch.arange(1 * 16 * 7 * 8 * 8, dtype=torch.float32).reshape(1, 16, 7, 8, 8)
+
+    reference_vae = _SlicingDecodeVAE(slicing_latent_min_size=3)
+    expected = reference_vae.decode_(z)
+
+    tiled_vae_model = _SlicingDecodeVAE(slicing_latent_min_size=3)
+    actual = tiled_vae(
+        z,
+        tiled_vae_model,
+        tile_size=(64, 64),
+        tile_overlap=(0, 0),
+        temporal_size=0,
+        temporal_overlap=0,
+        encode=False,
+    )
+
+    assert torch.equal(actual, expected)
+    assert tiled_vae_model.decode_min_sizes == [7]
+    assert tiled_vae_model.memory_states == [MemoryState.DISABLED]
+    assert tiled_vae_model.slicing_latent_min_size == 3
+
+    spatial_vae = _LocalSpatialDecodeVAE()
+    spatial = tiled_vae(
+        torch.zeros(1, 16, 1, 8, 12),
+        spatial_vae,
+        tile_size=(64, 64),
+        tile_overlap=(0, 32),
+        encode=False,
+    )
+    ramp = 0.5 - 0.5 * torch.cos(torch.linspace(0, 1, steps=32) * torch.pi)
+    expected = (36.0 * (1.0 - ramp[4])) + (4.0 * ramp[4])
+
+    assert spatial_vae.tile_shapes == [
+        (1, 16, 1, 8, 8),
+        (1, 16, 1, 8, 8),
+    ]
+    assert torch.isclose(spatial[0, 0, 0, 0, 36], expected)
+
+
+def test_decode_tiled_vae_clamps_overlap_sized_tiles_to_preserve_coverage():
+    spatial_vae = _LocalSpatialDecodeVAE()
+    spatial = tiled_vae(
+        torch.zeros(1, 16, 1, 8, 12),
+        spatial_vae,
+        tile_size=(64, 64),
+        tile_overlap=(0, 128),
+        encode=False,
+    )
+
+    assert len(spatial_vae.tile_shapes) > 1
+    assert torch.count_nonzero(spatial[0, 0, 0, 0, 64:]) > 0
diff --git a/tests-unit/comfy_test/test_vae_decode_tiled_dispatcher_seedvr2_4d.py b/tests-unit/comfy_test/test_vae_decode_tiled_dispatcher_seedvr2_4d.py
new file mode 100644
index 000000000..c655867ce
--- /dev/null
+++ b/tests-unit/comfy_test/test_vae_decode_tiled_dispatcher_seedvr2_4d.py
@@ -0,0 +1,165 @@
+"""Unit test for the ``VAE.decode`` tiled-fallback dispatcher routing of
+SeedVR2 latents in their 4D collapsed form ``(B, 16*T, H, W)``.
+
+Regression: the dispatcher branch at ``comfy/sd.py``'s
+``VAE.decode -> if do_tile: ... elif dims == 2`` previously routed
+``ndim == 4`` SeedVR2 latents to the generic ``decode_tiled_``, whose
+``tiled_scale`` mask broadcast does not understand the
+``(16, T)`` channel-time collapse and crashed with
+``"The size of tensor a (1024) must match the size of tensor b (256)
+at non-singleton dimension 4"``.
+
+Post-fix: when the wrapped model is a
+``comfy.ldm.seedvr.vae.VideoAutoencoderKLWrapper`` and the input is 4D,
+the dispatcher must route to ``decode_tiled_seedvr2`` instead. This
+test verifies the dispatcher selection without invoking the actual VAE
+math (which would require real model weights and a GPU): the two
+candidate methods are patched, the regular decode is forced to OOM via
+a stub, and the test asserts that ``decode_tiled_seedvr2`` is called
+exactly once (and ``decode_tiled_`` zero times) for a 4D SeedVR2
+input.
+"""
+
+from unittest.mock import MagicMock, patch
+
+import torch
+
+from comfy.cli_args import args as cli_args
+
+if not torch.cuda.is_available():
+    cli_args.cpu = True
+
+import comfy.ldm.seedvr.vae as seedvr_vae_mod  # noqa: E402
+import comfy.sd as sd_mod  # noqa: E402
+
+
+def _make_minimal_seedvr2_vae():
+    """Construct a ``comfy.sd.VAE`` instance whose ``first_stage_model``
+    is a real ``VideoAutoencoderKLWrapper`` (built via ``__new__`` to
+    skip weight allocation), with the VAE's other attributes stubbed
+    to the minimum that ``VAE.decode``'s regular-decode setup path
+    requires before the OOM forced fallback.
+    """
+    vae = sd_mod.VAE.__new__(sd_mod.VAE)
+    wrapper = seedvr_vae_mod.VideoAutoencoderKLWrapper.__new__(
+        seedvr_vae_mod.VideoAutoencoderKLWrapper
+    )
+    vae.first_stage_model = wrapper
+
+    # Minimum surface that ``VAE.decode`` touches before tiled fallback:
+    vae.patcher = MagicMock()
+    vae.patcher.get_free_memory = MagicMock(return_value=8 * 1024 * 1024 * 1024)
+    vae.device = torch.device("cpu")
+    vae.output_device = torch.device("cpu")
+    vae.vae_dtype = torch.float32
+    vae.disable_offload = True
+    vae.extra_1d_channel = None
+    vae.upscale_ratio = 8
+    vae.upscale_index_formula = None
+    vae.output_channels = 3
+    vae.latent_channels = 16
+    vae.latent_dim = 3  # SeedVR2 is a 3D-temporal latent format (T, H, W)
+    vae.downscale_ratio = 8
+    vae.downscale_index_formula = None
+
+    vae.vae_output_dtype = lambda: torch.float32
+    vae.spacial_compression_decode = lambda: 8
+    vae.process_input = lambda x: x
+    vae.process_output = lambda x: x
+    vae.throw_exception_if_invalid = lambda: None
+    vae.memory_used_decode = lambda *a, **k: 1
+    return vae
+
+
+def _force_regular_decode_oom(*args, **kwargs):
+    """Stub ``first_stage_model.decode`` to raise an OOM-shaped error
+    so ``VAE.decode``'s ``except`` branch sets ``do_tile = True`` and
+    falls into the tiled-fallback dispatcher.
+    """
+    raise torch.cuda.OutOfMemoryError("forced OOM for dispatcher test")
+
+
+def test_4d_seedvr2_latent_routes_to_decode_tiled_seedvr2():
+    vae = _make_minimal_seedvr2_vae()
+    samples_4d = torch.zeros(1, 16 * 3, 8, 8)  # (B, 16*T, H, W), T=3
+
+    seedvr2_call = MagicMock(return_value=torch.zeros(1, 3, 9, 64, 64))
+    generic_call = MagicMock(return_value=torch.zeros(1, 3, 64, 64))
+
+    with patch.object(sd_mod.model_management, "raise_non_oom",
+                      lambda e: None), \
+         patch.object(sd_mod.model_management, "load_models_gpu",
+                      lambda *a, **k: None), \
+         patch.object(sd_mod.model_management, "soft_empty_cache",
+                      lambda: None), \
+         patch.object(seedvr_vae_mod.VideoAutoencoderKLWrapper, "decode",
+                      side_effect=_force_regular_decode_oom), \
+         patch.object(sd_mod.VAE, "decode_tiled_seedvr2", seedvr2_call), \
+         patch.object(sd_mod.VAE, "decode_tiled_", generic_call):
+        vae.decode(samples_4d)
+
+    assert seedvr2_call.call_count == 1, (
+        f"Expected decode_tiled_seedvr2 to be called once for a 4D SeedVR2 "
+        f"latent under tiled fallback; got {seedvr2_call.call_count} calls."
+    )
+    assert generic_call.call_count == 0, (
+        f"decode_tiled_ must NOT be called for a 4D SeedVR2 latent; got "
+        f"{generic_call.call_count} calls. Pre-fix dispatcher would route "
+        f"to this method and crash inside tiled_scale's mask broadcast."
+    )
+
+
+def test_4d_non_seedvr2_latent_still_routes_to_generic_decode_tiled():
+    """The dispatcher fix must NOT affect non-SeedVR2 4D latents: any
+    other VAE whose ``first_stage_model`` is not a
+    ``VideoAutoencoderKLWrapper`` continues to route to the generic
+    ``decode_tiled_``.
+    """
+    vae = sd_mod.VAE.__new__(sd_mod.VAE)
+    vae.first_stage_model = MagicMock()  # NOT a VideoAutoencoderKLWrapper
+
+    vae.patcher = MagicMock()
+    vae.patcher.get_free_memory = MagicMock(return_value=8 * 1024 * 1024 * 1024)
+    vae.device = torch.device("cpu")
+    vae.output_device = torch.device("cpu")
+    vae.vae_dtype = torch.float32
+    vae.disable_offload = True
+    vae.extra_1d_channel = None
+    vae.upscale_ratio = 8
+    vae.upscale_index_formula = None
+    vae.output_channels = 3
+    vae.latent_channels = 4
+    vae.latent_dim = 2
+    vae.downscale_ratio = 8
+    vae.downscale_index_formula = None
+    vae.vae_output_dtype = lambda: torch.float32
+    vae.spacial_compression_decode = lambda: 8
+    vae.process_output = lambda x: x
+    vae.throw_exception_if_invalid = lambda: None
+    vae.memory_used_decode = lambda *a, **k: 1
+    vae.first_stage_model.decode = MagicMock(
+        side_effect=_force_regular_decode_oom
+    )
+
+    samples_4d = torch.zeros(1, 4, 8, 8)
+    generic_call = MagicMock(return_value=torch.zeros(1, 3, 64, 64))
+    seedvr2_call = MagicMock(return_value=torch.zeros(1, 3, 9, 64, 64))
+
+    with patch.object(sd_mod.model_management, "raise_non_oom",
+                      lambda e: None), \
+         patch.object(sd_mod.model_management, "load_models_gpu",
+                      lambda *a, **k: None), \
+         patch.object(sd_mod.model_management, "soft_empty_cache",
+                      lambda: None), \
+         patch.object(sd_mod.VAE, "decode_tiled_seedvr2", seedvr2_call), \
+         patch.object(sd_mod.VAE, "decode_tiled_", generic_call):
+        vae.decode(samples_4d)
+
+    assert generic_call.call_count == 1, (
+        f"Expected decode_tiled_ to be called once for a non-SeedVR2 4D "
+        f"latent; got {generic_call.call_count} calls."
+    )
+    assert seedvr2_call.call_count == 0, (
+        f"decode_tiled_seedvr2 must NOT be called for non-SeedVR2 latents; "
+        f"got {seedvr2_call.call_count} calls."
+    )
diff --git a/tests-unit/comfy_test/test_vae_encode_tiled_explicit_dispatcher_seedvr2.py b/tests-unit/comfy_test/test_vae_encode_tiled_explicit_dispatcher_seedvr2.py
new file mode 100644
index 000000000..e50168111
--- /dev/null
+++ b/tests-unit/comfy_test/test_vae_encode_tiled_explicit_dispatcher_seedvr2.py
@@ -0,0 +1,119 @@
+"""Unit tests for the explicit ``VAE.encode_tiled`` dispatcher routing of
+SeedVR2 vs non-SeedVR2 3D inputs.
+
+Mirrors the decode-side dispatcher contract in
+``test_vae_decode_tiled_dispatcher_seedvr2_4d.py`` and the encode OOM
+fallback contract in ``test_vae_encode_tiled_fallback_dispatcher_seedvr2.py``:
+the two candidate methods (``encode_tiled_seedvr2``, ``encode_tiled_3d``)
+are patched on the ``VAE`` class, ``encode_tiled`` is invoked directly,
+and the test asserts the dispatcher selects the SeedVR2-aware tiler when
+``first_stage_model`` is a ``VideoAutoencoderKLWrapper`` while preserving
+the generic 3D tiler for non-SeedVR2 inputs.
+"""
+
+from unittest.mock import MagicMock, patch
+
+import torch
+
+from comfy.cli_args import args as cli_args
+
+if not torch.cuda.is_available():
+    cli_args.cpu = True
+
+import comfy.ldm.seedvr.vae as seedvr_vae_mod  # noqa: E402
+import comfy.sd as sd_mod  # noqa: E402
+
+
+def _populate_common_vae_attrs(vae):
+    vae.patcher = MagicMock()
+    vae.patcher.get_free_memory = MagicMock(return_value=8 * 1024 * 1024 * 1024)
+    vae.device = torch.device("cpu")
+    vae.output_device = torch.device("cpu")
+    vae.vae_dtype = torch.float32
+    vae.disable_offload = True
+    vae.extra_1d_channel = None
+    vae.upscale_ratio = [lambda x: x]
+    vae.upscale_index_formula = None
+    vae.output_channels = 3
+    vae.latent_channels = 16
+    vae.latent_dim = 3
+    vae.downscale_ratio = [lambda x: x]
+    vae.downscale_index_formula = None
+    vae.not_video = False
+    vae.crop_input = False
+    vae.pad_channel_value = None
+
+    vae.vae_output_dtype = lambda: torch.float32
+    vae.spacial_compression_encode = lambda: 8
+    vae.vae_encode_crop_pixels = lambda x: x
+    vae.throw_exception_if_invalid = lambda: None
+    vae.memory_used_encode = lambda *a, **k: 1
+
+
+def _make_seedvr2_vae():
+    vae = sd_mod.VAE.__new__(sd_mod.VAE)
+    wrapper = seedvr_vae_mod.VideoAutoencoderKLWrapper.__new__(
+        seedvr_vae_mod.VideoAutoencoderKLWrapper
+    )
+    vae.first_stage_model = wrapper
+    _populate_common_vae_attrs(vae)
+    return vae
+
+
+def _make_non_seedvr2_vae():
+    vae = sd_mod.VAE.__new__(sd_mod.VAE)
+    vae.first_stage_model = MagicMock()
+    _populate_common_vae_attrs(vae)
+    return vae
+
+
+def test_explicit_encode_tiled_seedvr2_3d_routes_to_seedvr2_tiler():
+    vae = _make_seedvr2_vae()
+    pixel_samples = torch.zeros((1, 64, 64, 3))
+
+    seedvr2_call = MagicMock(return_value=torch.zeros(1, 16, 2, 8, 8))
+    generic_call = MagicMock(return_value=torch.zeros(1, 16, 2, 8, 8))
+
+    with patch.object(sd_mod.model_management, "load_models_gpu",
+                      lambda *a, **k: None), \
+         patch.object(sd_mod.VAE, "encode_tiled_seedvr2", seedvr2_call,
+                      create=True), \
+         patch.object(sd_mod.VAE, "encode_tiled_3d", generic_call):
+        vae.encode_tiled(pixel_samples)
+
+    assert seedvr2_call.call_count == 1, (
+        f"Expected encode_tiled_seedvr2 to be called once for a SeedVR2 3D "
+        f"input via explicit encode_tiled; got {seedvr2_call.call_count} calls."
+    )
+    assert generic_call.call_count == 0, (
+        f"encode_tiled_3d must NOT be called for a SeedVR2 input via explicit "
+        f"encode_tiled; got {generic_call.call_count} calls."
+    )
+
+
+def test_explicit_encode_tiled_dispatcher_breakdown():
+    seedvr2_call = MagicMock(return_value=torch.zeros(1, 16, 2, 8, 8))
+    generic_call = MagicMock(return_value=torch.zeros(1, 16, 2, 8, 8))
+
+    seedvr2_vae = _make_seedvr2_vae()
+    non_seedvr2_vae = _make_non_seedvr2_vae()
+
+    pixel_samples = torch.zeros((1, 64, 64, 3))
+
+    with patch.object(sd_mod.model_management, "load_models_gpu",
+                      lambda *a, **k: None), \
+         patch.object(sd_mod.VAE, "encode_tiled_seedvr2", seedvr2_call,
+                      create=True), \
+         patch.object(sd_mod.VAE, "encode_tiled_3d", generic_call):
+        seedvr2_vae.encode_tiled(pixel_samples)
+        non_seedvr2_vae.encode_tiled(pixel_samples)
+
+    assert seedvr2_call.call_count == 1, (
+        f"Expected encode_tiled_seedvr2 called once across SeedVR2 + "
+        f"non-SeedVR2 explicit encode_tiled calls; got "
+        f"{seedvr2_call.call_count}."
+    )
+    assert generic_call.call_count == 1, (
+        f"Expected encode_tiled_3d called once across SeedVR2 + non-SeedVR2 "
+        f"explicit encode_tiled calls; got {generic_call.call_count}."
+    )
diff --git a/tests-unit/comfy_test/test_vae_encode_tiled_fallback_dispatcher_seedvr2.py b/tests-unit/comfy_test/test_vae_encode_tiled_fallback_dispatcher_seedvr2.py
new file mode 100644
index 000000000..d533b5244
--- /dev/null
+++ b/tests-unit/comfy_test/test_vae_encode_tiled_fallback_dispatcher_seedvr2.py
@@ -0,0 +1,184 @@
+"""Unit tests for the ``VAE.encode`` OOM-fallback dispatcher routing of
+SeedVR2 vs non-SeedVR2 3D inputs.
+
+Mirrors the decode-side dispatcher contract in
+``test_vae_decode_tiled_dispatcher_seedvr2_4d.py``: the two candidate
+methods (``encode_tiled_seedvr2``, ``encode_tiled_3d``) are patched on
+the ``VAE`` class, the regular encode is forced to OOM via a stub, and
+the test asserts the dispatcher selects the SeedVR2-aware tiler when
+``first_stage_model`` is a ``VideoAutoencoderKLWrapper`` while
+preserving the generic 3D tiler for non-SeedVR2 inputs.
+"""
+
+from unittest.mock import MagicMock, patch
+
+import torch
+
+from comfy.cli_args import args as cli_args
+
+if not torch.cuda.is_available():
+    cli_args.cpu = True
+
+import comfy.ldm.seedvr.vae as seedvr_vae_mod  # noqa: E402
+import comfy.sd as sd_mod  # noqa: E402
+
+
+def _populate_common_vae_attrs(vae):
+    vae.patcher = MagicMock()
+    vae.patcher.get_free_memory = MagicMock(return_value=8 * 1024 * 1024 * 1024)
+    vae.device = torch.device("cpu")
+    vae.output_device = torch.device("cpu")
+    vae.vae_dtype = torch.float32
+    vae.disable_offload = True
+    vae.extra_1d_channel = None
+    vae.upscale_ratio = 8
+    vae.upscale_index_formula = None
+    vae.output_channels = 3
+    vae.latent_channels = 16
+    vae.latent_dim = 3
+    vae.downscale_ratio = 8
+    vae.downscale_index_formula = None
+    vae.not_video = False
+    vae.crop_input = False
+    vae.pad_channel_value = None
+
+    vae.vae_output_dtype = lambda: torch.float32
+    vae.spacial_compression_encode = lambda: 8
+    vae.process_input = lambda x: x
+    vae.process_output = lambda x: x
+    vae.throw_exception_if_invalid = lambda: None
+    vae.memory_used_encode = lambda *a, **k: 1
+
+
+def _make_seedvr2_vae():
+    vae = sd_mod.VAE.__new__(sd_mod.VAE)
+    wrapper = seedvr_vae_mod.VideoAutoencoderKLWrapper.__new__(
+        seedvr_vae_mod.VideoAutoencoderKLWrapper
+    )
+    vae.first_stage_model = wrapper
+    _populate_common_vae_attrs(vae)
+    return vae
+
+
+def _make_non_seedvr2_vae():
+    vae = sd_mod.VAE.__new__(sd_mod.VAE)
+    vae.first_stage_model = MagicMock()
+    _populate_common_vae_attrs(vae)
+    return vae
+
+
+def _force_regular_encode_oom(*args, **kwargs):
+    raise torch.cuda.OutOfMemoryError("forced OOM for dispatcher test")
+
+
+def test_seedvr2_3d_routes_to_encode_tiled_seedvr2_on_oom():
+    vae = _make_seedvr2_vae()
+    pixel_samples = torch.zeros((1, 8, 64, 64, 3))
+
+    seedvr2_call = MagicMock(return_value=torch.zeros(1, 16, 2, 8, 8))
+    generic_call = MagicMock(return_value=torch.zeros(1, 16, 2, 8, 8))
+
+    with patch.object(sd_mod.model_management, "raise_non_oom",
+                      lambda e: None), \
+         patch.object(sd_mod.model_management, "load_models_gpu",
+                      lambda *a, **k: None), \
+         patch.object(sd_mod.model_management, "soft_empty_cache",
+                      lambda: None), \
+         patch.object(seedvr_vae_mod.VideoAutoencoderKLWrapper, "encode",
+                      side_effect=_force_regular_encode_oom), \
+         patch.object(sd_mod.VAE, "encode_tiled_seedvr2", seedvr2_call,
+                      create=True), \
+         patch.object(sd_mod.VAE, "encode_tiled_3d", generic_call):
+        vae.encode(pixel_samples)
+
+    assert seedvr2_call.call_count == 1, (
+        f"Expected encode_tiled_seedvr2 to be called once for a SeedVR2 3D "
+        f"input under OOM fallback; got {seedvr2_call.call_count} calls."
+    )
+    assert generic_call.call_count == 0, (
+        f"encode_tiled_3d must NOT be called for a SeedVR2 input; got "
+        f"{generic_call.call_count} calls."
+    )
+
+
+def test_seedvr2_oom_fallback_uses_explicit_seedvr2_tile_defaults():
+    vae = _make_seedvr2_vae()
+    vae.first_stage_model.tiled_args = {
+        "tile_size": (128, 128),
+        "tile_overlap": (32, 32),
+        "temporal_size": 12,
+        "temporal_overlap": 4,
+    }
+    pixel_samples = torch.zeros((1, 8, 64, 64, 3))
+
+    seedvr2_call = MagicMock(return_value=torch.zeros(1, 16, 2, 8, 8))
+
+    with patch.object(sd_mod.model_management, "raise_non_oom",
+                      lambda e: None), \
+         patch.object(sd_mod.model_management, "load_models_gpu",
+                      lambda *a, **k: None), \
+         patch.object(sd_mod.model_management, "soft_empty_cache",
+                      lambda: None), \
+         patch.object(seedvr_vae_mod.VideoAutoencoderKLWrapper, "encode",
+                      side_effect=_force_regular_encode_oom), \
+         patch.object(sd_mod.VAE, "encode_tiled_seedvr2", seedvr2_call,
+                      create=True):
+        vae.encode(pixel_samples)
+
+    assert seedvr2_call.call_count == 1
+    assert seedvr2_call.call_args.kwargs == {
+        "tile_x": 256,
+        "tile_y": 256,
+        "overlap": 64,
+    }
+
+
+def test_oom_fallback_dispatcher_breakdown():
+    seedvr2_call = MagicMock(return_value=torch.zeros(1, 16, 2, 8, 8))
+    generic_call = MagicMock(return_value=torch.zeros(1, 16, 2, 8, 8))
+
+    seedvr2_vae = _make_seedvr2_vae()
+    non_seedvr2_vae = _make_non_seedvr2_vae()
+    non_seedvr2_vae.first_stage_model.encode = MagicMock(
+        side_effect=_force_regular_encode_oom
+    )
+
+    pixel_samples = torch.zeros((1, 8, 64, 64, 3))
+
+    with patch.object(sd_mod.model_management, "raise_non_oom",
+                      lambda e: None), \
+         patch.object(sd_mod.model_management, "load_models_gpu",
+                      lambda *a, **k: None), \
+         patch.object(sd_mod.model_management, "soft_empty_cache",
+                      lambda: None), \
+         patch.object(seedvr_vae_mod.VideoAutoencoderKLWrapper, "encode",
+                      side_effect=_force_regular_encode_oom), \
+         patch.object(sd_mod.VAE, "encode_tiled_seedvr2", seedvr2_call,
+                      create=True), \
+         patch.object(sd_mod.VAE, "encode_tiled_3d", generic_call):
+        seedvr2_vae.encode(pixel_samples)
+        non_seedvr2_vae.encode(pixel_samples)
+
+    assert seedvr2_call.call_count == 1, (
+        f"Expected encode_tiled_seedvr2 called once across SeedVR2 + "
+        f"non-SeedVR2 OOM fallbacks; got {seedvr2_call.call_count}."
+    )
+    assert generic_call.call_count == 1, (
+        f"Expected encode_tiled_3d called once across SeedVR2 + non-SeedVR2 "
+        f"OOM fallbacks; got {generic_call.call_count}."
+    )
+
+
+def test_non_seedvr2_encode_tiled_3d_default_overlap_is_concrete():
+    vae = _make_non_seedvr2_vae()
+    vae.downscale_ratio = (lambda a: max(1, a // 4), 8, 8)
+    vae.upscale_ratio = (lambda a: a * 4, 8, 8)
+    generic_call = MagicMock(return_value=torch.zeros(1, 16, 2, 8, 8))
+    pixel_samples = torch.zeros((1, 8, 64, 64, 3))
+
+    with patch.object(sd_mod.model_management, "load_models_gpu",
+                      lambda *a, **k: None), \
+         patch.object(sd_mod.VAE, "encode_tiled_3d", generic_call):
+        vae.encode_tiled(pixel_samples)
+
+    assert generic_call.call_args.kwargs["overlap"] == (1, 64, 64)
diff --git a/tests-unit/comfy_test/test_vae_encode_tiled_seedvr2_method.py b/tests-unit/comfy_test/test_vae_encode_tiled_seedvr2_method.py
new file mode 100644
index 000000000..0013cd6ed
--- /dev/null
+++ b/tests-unit/comfy_test/test_vae_encode_tiled_seedvr2_method.py
@@ -0,0 +1,205 @@
+"""Unit tests for ``VAE.encode_tiled_seedvr2``: existence with the
+SeedVR2 tile-shape signature and delegation through
+``comfy.ldm.seedvr.vae.tiled_vae(..., encode=True)`` with one call per
+spatial tile.
+
+Mirrors the decode-side method-existence + delegation contract for
+``VAE.decode_tiled_seedvr2``; CPU-only via mocks and a
+``VideoAutoencoderKLWrapper.__new__`` wrapper stub (no weights, no
+GPU).
+"""
+
+import inspect
+from unittest.mock import MagicMock, patch
+
+import torch
+
+from comfy.cli_args import args as cli_args
+
+if not torch.cuda.is_available():
+    cli_args.cpu = True
+
+import comfy.ldm.seedvr.vae as seedvr_vae_mod  # noqa: E402
+import comfy.sd as sd_mod  # noqa: E402
+import nodes as nodes_mod  # noqa: E402
+
+
+def _make_minimal_seedvr2_vae():
+    vae = sd_mod.VAE.__new__(sd_mod.VAE)
+    wrapper = seedvr_vae_mod.VideoAutoencoderKLWrapper.__new__(
+        seedvr_vae_mod.VideoAutoencoderKLWrapper
+    )
+    vae.first_stage_model = wrapper
+
+    vae.device = torch.device("cpu")
+    vae.output_device = torch.device("cpu")
+    vae.vae_dtype = torch.float32
+    vae.latent_channels = 16
+    vae.latent_dim = 3
+    vae.downscale_ratio = 8
+
+    vae.vae_output_dtype = lambda: torch.float32
+    vae.process_input = lambda x: x
+    return vae
+
+
+def test_method_exists_with_seedvr2_signature():
+    assert hasattr(sd_mod.VAE, "encode_tiled_seedvr2"), (
+        "VAE.encode_tiled_seedvr2 must be defined on the VAE class."
+    )
+    sig = inspect.signature(sd_mod.VAE.encode_tiled_seedvr2)
+    params = list(sig.parameters)
+    for required in ("self", "pixel_samples", "tile_x", "tile_y",
+                     "overlap", "tile_t", "overlap_t"):
+        assert required in params, (
+            f"VAE.encode_tiled_seedvr2 missing required parameter "
+            f"{required!r}; got parameters {params}."
+        )
+
+
+def test_vae_encode_tiled_allows_zero_temporal_controls_and_passes_zero_through():
+    input_types = nodes_mod.VAEEncodeTiled.INPUT_TYPES()["required"]
+    assert input_types["temporal_size"][1]["min"] == 0
+    assert input_types["temporal_overlap"][1]["min"] == 0
+    assert "SeedVR2 allows 0" in input_types["temporal_size"][1]["tooltip"]
+
+    class _EncodeRecorder:
+        def __init__(self):
+            self.calls = []
+
+        def encode_tiled(self, pixels, **kwargs):
+            self.calls.append({"shape": tuple(pixels.shape), **kwargs})
+            return torch.zeros(1, 16, 1, 8, 8)
+
+    recorder = _EncodeRecorder()
+    node = nodes_mod.VAEEncodeTiled()
+
+    output = node.encode(
+        recorder,
+        torch.zeros(1, 64, 64, 3),
+        tile_size=256,
+        overlap=64,
+        temporal_size=0,
+        temporal_overlap=8,
+    )
+
+    assert recorder.calls == [
+        {
+            "shape": (1, 64, 64, 3),
+            "tile_x": 256,
+            "tile_y": 256,
+            "overlap": 64,
+            "tile_t": 0,
+            "overlap_t": 0,
+        }
+    ]
+    assert torch.equal(output[0]["samples"], torch.zeros(1, 16, 1, 8, 8))
+
+
+def test_method_routes_through_tiled_vae_encode_true():
+    vae = _make_minimal_seedvr2_vae()
+    pixel_samples = torch.zeros((1, 3, 8, 64, 64))
+
+    tiled_vae_mock = MagicMock(return_value=torch.zeros((1, 16, 2, 8, 8)))
+
+    with patch.object(seedvr_vae_mod, "tiled_vae", tiled_vae_mock):
+        vae.encode_tiled_seedvr2(pixel_samples)
+
+    assert tiled_vae_mock.call_count >= 1, (
+        f"Expected encode_tiled_seedvr2 to delegate to tiled_vae at "
+        f"least once; got {tiled_vae_mock.call_count} calls."
+    )
+    for call in tiled_vae_mock.call_args_list:
+        assert call.kwargs.get("encode") is True, (
+            f"Every tiled_vae delegation from encode_tiled_seedvr2 must "
+            f"pass encode=True; got kwargs={call.kwargs!r}."
+        )
+
+
+def test_method_sets_wrapper_device_before_tiled_vae():
+    vae = _make_minimal_seedvr2_vae()
+    pixel_samples = torch.zeros((1, 3, 8, 64, 64))
+    assert not hasattr(vae.first_stage_model, "device")
+
+    def _assert_device_initialized(*args, **kwargs):
+        vae_model = args[1]
+        assert vae_model.device == vae.device
+        return torch.zeros((1, 16, 2, 8, 8))
+
+    with patch.object(seedvr_vae_mod, "tiled_vae",
+                      MagicMock(side_effect=_assert_device_initialized)):
+        vae.encode_tiled_seedvr2(pixel_samples)
+
+
+def test_method_honors_explicit_tile_parameters_over_stale_wrapper_args():
+    vae = _make_minimal_seedvr2_vae()
+    pixel_samples = torch.zeros((1, 3, 8, 64, 64))
+    vae.first_stage_model.tiled_args = {
+        "tile_size": (17, 19),
+        "tile_overlap": (3, 5),
+        "temporal_size": 7,
+        "temporal_overlap": 2,
+        "preserved": "value",
+    }
+
+    tiled_vae_mock = MagicMock(return_value=torch.zeros((1, 16, 2, 8, 8)))
+
+    with patch.object(seedvr_vae_mod, "tiled_vae", tiled_vae_mock):
+        vae.encode_tiled_seedvr2(
+            pixel_samples,
+            tile_x=96,
+            tile_y=80,
+            overlap=12,
+            tile_t=11,
+            overlap_t=4,
+        )
+
+    assert tiled_vae_mock.call_args.kwargs["tile_size"] == (80, 96)
+    assert tiled_vae_mock.call_args.kwargs["tile_overlap"] == (12, 12)
+    assert tiled_vae_mock.call_args.kwargs["temporal_size"] == 11
+    assert tiled_vae_mock.call_args.kwargs["temporal_overlap"] == 4
+    assert vae.first_stage_model.tiled_args["preserved"] == "value"
+
+
+def test_method_uses_explicit_defaults_when_call_omits_tile_parameters():
+    vae = _make_minimal_seedvr2_vae()
+    pixel_samples = torch.zeros((1, 3, 8, 64, 64))
+    vae.first_stage_model.tiled_args = {
+        "tile_size": (128, 160),
+        "tile_overlap": (16, 24),
+        "temporal_size": 9,
+        "temporal_overlap": 1,
+    }
+
+    tiled_vae_mock = MagicMock(return_value=torch.zeros((1, 16, 2, 8, 8)))
+
+    with patch.object(seedvr_vae_mod, "tiled_vae", tiled_vae_mock):
+        vae.encode_tiled_seedvr2(pixel_samples)
+
+    assert tiled_vae_mock.call_args.kwargs["tile_size"] == (512, 512)
+    assert tiled_vae_mock.call_args.kwargs["tile_overlap"] == (64, 64)
+    assert tiled_vae_mock.call_args.kwargs["temporal_size"] == 9999
+    assert tiled_vae_mock.call_args.kwargs["temporal_overlap"] == 0
+    assert vae.first_stage_model.tiled_args == {
+        "tile_size": (128, 160),
+        "tile_overlap": (16, 24),
+        "temporal_size": 9,
+        "temporal_overlap": 1,
+    }
+
+
+def test_method_clamps_overlap_below_tile_size():
+    vae = _make_minimal_seedvr2_vae()
+    pixel_samples = torch.zeros((1, 3, 8, 64, 64))
+
+    tiled_vae_mock = MagicMock(return_value=torch.zeros((1, 16, 2, 8, 8)))
+
+    with patch.object(seedvr_vae_mod, "tiled_vae", tiled_vae_mock):
+        vae.encode_tiled_seedvr2(
+            pixel_samples,
+            tile_x=64,
+            tile_y=48,
+            overlap=96,
+        )
+
+    assert tiled_vae_mock.call_args.kwargs["tile_overlap"] == (40, 56)