Destination says the format is unsupported - causes and fixes
An unsupported-format error may refer to the container, the codec inside the container, or the upload surface. The filename extension alone cannot distinguish these. Confirm the destination's documented format list and re-export from the original if needed.
Check these first
- Confirm the destination's published format list (organic / web / API can differ).
- Inspect the actual container and codec with a media inspector (File Doctor).
- Try opening the file in a standard player to rule out a corrupted export.
Likely causes
- Container is not in the destination's published list
Editing formats (ProRes, DNxHR) are often rejected even when wrapped in MP4/MOV.
- Codec inside an accepted container is not decoded
MP4 / MOV can hold many codecs; H.264/H.265 are widely decoded, others vary.
- Filename is misleading
An .mp4 file containing editing codec data is still an editing file.
Fix it
- Re-export with a destination-appropriate container + codec
Re-encode the original with MP4/H.264/AAC unless a different combination is documented for this surface.
Re-export with a destination-appropriate container + codec
Check your file
Extension and MIME type are labels, not proof of the container. Dimensions and duration come from this browser's media reader. This does not detect codecs, bitrate, corruption or platform upload compatibility. Files and measurements are not sent anywhere.
Prepare a copy in Koldflux, review its output and check the current destination requirements before publishing.
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