Troubleshooting browser video upscaling

The video cannot be opened

Confirm that the file is really MP4 or WebM. Changing its extension does not change the codec. If the message mentions HEVC or HDR, export an 8-bit SDR H.264 MP4 with AAC audio in your editor. If even the first frame fails, check that the original file plays and is not incomplete. A screen recording with unusual or changing dimensions may need a fixed-resolution export.

The preview fails or processing is slow

Enable browser hardware acceleration, update the browser and restart it. Close other GPU-heavy applications. A model download failure may be a connection problem; only the selected model is fetched. A memory warning means you should choose Fast, use a smaller input or trim the clip. Enlarging a low-resolution source is less expensive than applying a network to full HD.

The measured preview estimate covers repeated inference on one frame. Encoding and decoding add time, and thermal throttling can change speed. Pause at a safe frame boundary, keep the tab open and resume when ready. Cancel releases the worker; it does not create a completed video. Do not refresh a paused job expecting it to resume later.

Audio or saving is unavailable

An incompatible soundtrack is a preflight error, not a reason to export silently. Re-export with AAC for MP4 or Opus for WebM. All audio tracks must fit the selected container. For an output too large to keep in memory, choose direct saving if available or shorten the clip.

If disk saving is denied, cancel the picker and use the download option. A cancelled direct job aborts pending writes; after a forced worker termination, inspect the selected destination for an unfinished file. Browser memory errors can terminate a tab without a recoverable download. Keep the source until your final output is verified.