Convert MP4 to GIF

GIF has no motion compensation. Video formats work by storing one complete frame and then, for every frame after it, only the difference — which is why a two-minute talking-head video with a static background can be a few megabytes. GIF stores each frame as an entire picture, one after another, forever.

The consequence is a size curve that catches people out. Ten seconds of ordinary footage as a GIF is comfortably larger than the whole MP4 it came from, often by a factor of ten or twenty. There is no setting that fixes this and no converter that avoids it; it is the format, unchanged since 1989. What can be done is to give it less to store, which is what the three settings under the result are for.

Length, width and frame rate each multiply the size almost directly, and they are worth understanding because the defaults are conservative on purpose. Frame rate is linear: doubling from twelve to twenty-four roughly doubles the file, because it doubles the number of complete images. Width is quadratic: halving it quarters the size, because area scales with the square of the edge.

Measured on the same clip while building this page: 320 pixels wide at 8 frames a second produced 209 KB, while 640 pixels at 20 frames a second produced 781 KB — and the second of those was from *two* seconds of footage against three. That is the whole lesson in one comparison: a shorter clip at a higher setting can easily be larger than a longer one at a sensible setting.

If the place you are pasting this accepts video, paste video. Every major platform has for years — Twitter and Reddit convert uploaded GIFs to video silently, because they are paying for the bandwidth. A WebM of the same animation is dramatically smaller and looks better: converting a 448 KB GIF back to WebM in our own testing produced 19 KB. Four per cent, playing identically.

GIF earns its place where nothing else is accepted: an older forum, a wiki, a company intranet, an email signature, a documentation generator, a chat platform that treats GIF specially. If your destination is one of those, this is the right conversion and the settings below are how to make it fit. If it is not, convert the MP4 to WebM instead and save yourself the size and the banding.

A GIF frame can contain at most 256 distinct colours, and video frames routinely contain tens of thousands. Every frame therefore has to be reduced, and how visible that is depends entirely on the footage. A screen recording of an interface — flat panels, solid text, few colours — comes through almost untouched, which is why software demos are the one case where GIF still genuinely works.

Real footage does not fare as well. Skin tones, skies and any gradual shift of light break into visible bands. Each frame here is given its own palette rather than sharing one across the clip, which is the better of the two approaches and matters most when the scene changes: a single shared palette leaves everything after a cut rendered in the previous scene’s colours.

Your browser already decodes MP4 — it does it on every site that plays video. This page uses that decoder, samples the frames it wants, reduces each one to a palette and writes the GIF, all in the tab you have open. Nothing is uploaded and no account is involved.

That is worth pointing out here because GIF making is one of the most upload-hungry corners of the internet: running ffmpeg on a server is simply easier than doing this properly in a browser, so nearly everyone does. You can check which kind of site you are on in ten seconds — open your developer tools, watch the network tab, convert something, and see whether your video goes anywhere.