LinkedIn video ad needs an uploaded file, not a link: use the Sume MP4

A LinkedIn video ad must be a video file uploaded directly to LinkedIn, not a link to a third-party site like YouTube or Vimeo. For a clip made on Sume, that means downloading the MP4 from the finished job and uploading that file, after you check its length, size and frame rate against LinkedIn's spec.

The numbers below come from LinkedIn's video ads specifications, read on 2026-10-07. Sume's side comes from the video generation guide and video inspect.

What LinkedIn requires

The page lists one file rule that is easy to miss when a clip lives at a URL.

Get the file from a Sume job

A POST /v1/videos job returns an id and a polling URL. When the status is completed, the poll response holds unsigned_urls, and the content endpoint streams the file:

curl "https://api.sume.com/v1/videos/$JOB_ID/content?index=0" \
  -H "Authorization: Bearer $SUME_API_KEY" \
  --output ad.mp4

Check it before you upload

Do not trust the filename. Import the file back as a Sume asset only if you need to probe it: video inspect reads one media.sume.com clip that your workspace already owns and returns a probe object, and it can run with frames: false for the probe alone. Check these before you open LinkedIn's uploader:

• Duration at least 3 seconds. A very short generated clip can fall under it.
• Size under 500 MB. A short clip is far below it, but a long Timeline render is not a given.
• Container MP4 and a frame rate below 30. If your file is 30 or higher, conform it before upload.
• The long edge and the ratio, against the table above.

Where Sume stops

Sume makes and prepares the file. It does not upload to LinkedIn's ad account for you in the docs we checked, so the upload step is yours or your ad tool's. Generated outputs are mirrored into Sume-owned media.sume.com URLs, and the media inputs page says to store the Sume URL, not a raw provider URL. Keep that URL beside the LinkedIn ad id so you can trace an ad back to its generation job.

For the pixel sizes and the 4:5 case see the 4:5 spec check; for a Python size check see the file size check.