What happens when a platform processes a video
Most social and messaging platforms do not serve the creator’s exact upload. They decode the video and create new versions for different devices, bandwidths or aspect ratios. The visible scene may look almost identical while the underlying container, codec, metadata and frame data have changed.
Official artifact verification depends on technical signals in the media. If processing preserves enough of those signals, the copy may still match. If it removes them, a genuine Seedance output may return no match.
Which copies are most likely to lose the signal
There is no universal guarantee because each platform and export setting processes media differently. The practical rule is to count how many transformations separate your copy from the original generation output.
- Lower risk: original download from the generation platform.
- Moderate risk: one edit or transcode that keeps the full frame and duration.
- Higher risk: social-media download, messenger forwarding or aggressive compression.
- Highest risk: screen recording, cropped montage, short excerpt or repeated repost.
A failed check on a repost describes that copy. It does not conclusively describe the creator’s original file.
How to improve the chance of verification
Ask for the earliest available export, not another download of the same repost. Preserve its original filename and avoid opening and re-saving it in an editor before checking. If the source shared a cloud-storage link, download the file rather than screen-recording the player.
When a public link fails, upload the file directly. Many watch-page URLs require cookies, execute JavaScript or expire quickly, so they are not direct media links even though they play in a browser.
Report the result with the copy’s history
A responsible result should state which copy was checked: original export, platform download, forwarded file or screen recording. That context explains why a non-match may be weak evidence.
For investigations, preserve both the checked file and its SHA-256 hash. If a later original becomes available, check it separately instead of overwriting the earlier result.
Official references
This guide is based on the public ModelArk artifact-verification workflow. The provider documentation remains the source of truth for endpoint behavior.