VAE out of memory after sampling finishes: diagnose decoding separately

Symptoms and scope

Completed sampling still leaves latent data that must be decoded into pixels. A VAE failure after sampling therefore differs from memory exhaustion at the start of sampling.

Error fragments for search; IDs, values and filenames may vary:

VAEDecode
VAE decode
out of memory

Source-supported context

Official basic workflows separate KSampler and VAE Decode; video workflows also have their own VAE dependencies. There is no documented universal tile setting for all image and video VAEs. Source 1 Source 2 Source 3

Cases to distinguish

1. Spatial dimensions, frame count or decode batch size creates a peak while latents expand into images.

2. Other models or image branches remain resident during decoding.

3. The final error is actually a VAE compatibility, channel or dtype problem rather than OOM.

Diagnostic sequence

The sequence below is an editorial procedure based on the cited context, not a diagnosis already confirmed for your environment.

Step 1. Keep sampling settings and the report. Confirm that the traceback names VAE decoding rather than upscaling, preview or video encoding.

Step 2. Only if the specific workflow and model support smaller dimensions, fewer frames or a single-image decode, test one supported reduction at a time while keeping the same compatible VAE/model pairing.

Step 3. Try tiled decoding only where this version and VAE support it. Record tile size, overlap and temporal constraints; do not force an image decoder onto unsupported video latents.

Step 4. Inspect unnecessary parallel branches and model residency. If using an author-supported CPU/offload path, also monitor system RAM.

Completion check

Decoding produces valid pixels and the save stage succeeds. Inspect tile boundaries and temporal artifacts as well as process completion.

Limitations and cautions

Tiled and CPU decoding can affect speed, memory and numerical output. No minimum-VRAM benchmark is claimed here.

Original sources

• ComfyUI troubleshooting overview — original record checked 2026-09-21.
• Text-to-image workflow — original record checked 2026-09-21.
• Wan2.2 native workflows — original record checked 2026-09-21.

Localization prepared: 2026-09-22. The source-check dates above were inherited from the existing article; this translation does not claim they were all rechecked today. No GPU run, minimum-memory measurement or runtime guarantee is supplied.

Related troubleshooting and guides

• CUDA out of memory: separate model loading, sampling and VAE decoding
• VAE and latent channel mismatch: verify the exact variant, not just its family name
• Black images or invalid colors: separate sampling, VAE and display failures