X’s GIF limits
X accepts GIFs up to 15MB when posting from a browser, but only 5MB from the mobile apps. These numbers come from widely cited guides rather than an official help page, so we treat them as practical limits. If you post from your phone, drag the target slider down to 5MB — a GIF made for 5MB uploads everywhere.
Making it work in the timeline
- Square or 4:5 stands out — in a scrolling feed, a taller GIF takes up more screen. Use the 1:1 or 4:5 crop buttons above the settings.
- The first frame matters — X shows it before the GIF starts playing. Trim so the clip opens on something recognizable.
- Text needs an outline — X has light and dark modes; outlined text stays readable in both.
- Don’t over-size — the timeline displays GIFs at around 500–600px wide, so 480–640px is the sweet spot for 5MB.
GIF or video?
X converts uploaded GIFs into looping silent video behind the scenes, but they still behave like GIFs: autoplay, loop, and the GIF badge. If you need sound or longer than about 10 seconds, upload the video itself — the free VidCut editor can cut and crop it first.