X Ads card video: 10 minutes, 500 MB, MP4 or MOV, 16:9 or 1:1

X's Ads API creatives page lists video for cards as MP4 or MOV, up to 10 minutes and 500 MB, in 16:9 or 1:1 for website and app-download cards, with images at 3 MB or less (read 2026-10-02). I could not read X's separate ad-specs page, so check it for in-feed format limits before you ship.

What the API docs list

These are the Ads API card specs, not every X ad format. Some formats on X's business pages list other sizes, and I did not fetch those pages.

Fit a Sume clip to it

A Sume video job returns an MP4. Seedance 2.5 on Sume makes clips of 4 to 30 seconds (Video Router), far below 10 minutes, so length is not the problem; ratio is. Ask for 16:9 or 1:1 when you generate, or render with Timeline and set output.width and height (even values from 256 to 2160).

• Generate at 16:9 for poll, conversation and message cards.
• Use 1:1 for website cards if that is your placement.
• Cut an unwanted tail with video trim.
• Crop a vertical master to a square with video filter, which has an unbilled check endpoint.

Images and caveats

For stills, the Image API can output png, jpeg or webp on the Image 1.0 alias; X lists bmp, jpeg and png, so avoid webp (Image 1.0). A high-quality PNG can exceed 3 MB; Sume docs give no size cap, so check the file after download and re-export as JPEG if needed. Sume does not upload to X.