X animated GIF limit: 15 MB, 350 frames, and the MP4 alternative

X's best-practices page says an animated GIF must be 15 MB or smaller, and recommends 1280x1080 or less, 350 frames or fewer, and at most 300 million pixels (width x height x frames). Sume does not output GIF: generated clips are MP4 video, so for X a short MP4 is the Sume-side answer.

X figures are from its Media best practices page, read 2026-10-01. Sume facts are from Video generation and Video trim.

What are X's GIF limits?

X notes a GIF can fail at Post creation even within the size limit, so the recommendations matter. A Post takes up to 4 photos, 1 animated GIF or 1 video, never a mix.

Does Sume make GIFs?

No. A generated video is MP4: the output content_type is something like video/mp4. Auto create controls default to 720p and 8 seconds, with 3 to 10 second clips at 16:9 or 9:16.

What is the MP4 alternative?

Attach the MP4 as a video instead. A 350-frame GIF at 25 fps runs about 14 seconds, so a short MP4 loop covers the same ground, and X's video rules (not its GIF rules) then apply; see X video upload specs. To shorten a clip, use video-trim, whose duration accepts 0.2 to 900 seconds.

How do I do the frame arithmetic?

Multiply width, height and frames and compare with 300 million. For example, 1280 x 1080 x 350 is 483.8 million, over the recommendation, so a full-size, full-length GIF breaches the pixel budget even when it respects each other limit. Shrink the frame or drop frames, or use MP4.