Why GIFs are so much bigger than they should be
A GIF stores every frame as its own full image. There is no inter-frame compression — no concept of "this pixel is the same as the last frame, so skip it," which is the entire trick that makes MP4 and WebM tiny. So a three-second screen capture that would be a 300 KB MP4 routinely balloons to 8–15 MB as a GIF. The format dates to 1987 and was never designed for the high-resolution, high-frame-rate clips people make today. That is also why the two levers on this page matter so much: shrinking the width cuts the pixels-per-frame, and capping the color palette cuts the bytes-per-pixel. Multiply them across hundreds of frames and the savings compound fast.
Settings that actually move the needle
Start by lowering the width. Most GIFs are viewed in a chat sidebar or an inline comment at a fraction of their native size, so a 960 px GIF squeezed down to 480 px looks identical and is roughly a quarter of the file. Next, drop the color count. A screen recording with flat UI colors looks perfect at 64 colors; a colorful photo-real animation may need 128–256. This tool also caps the frame rate at 12 fps, which is plenty for screen content and a large saving on its own. If the result still is not small enough, push the width down before you sacrifice colors — resolution is almost always the cheaper thing to give up.
Targets for Slack, Discord, and email
Discord caps uploads at 10 MB on the free tier (25 MB before, since reduced), Gmail rejects attachments over 25 MB, and Slack will technically take more but throttles the inline preview on anything large. For all three, aim for the 2–6 MB range and your GIF will both upload and animate inline without nagging. If you keep blowing past those limits, that is usually a sign the clip is too long to be a GIF at all — which is the next section.
The honest answer: for big animations, share a video link
There is a ceiling to GIF compression. Past a few seconds, no amount of palette-trimming beats simply not using GIF. A 20-second walkthrough that is a stubborn 14 MB GIF is a 500 KB MP4 — and every modern chat app, doc tool, and email client now plays MP4 inline, so you lose nothing. If you are compressing a GIF to squeeze a product demo or a bug repro under an upload limit, the better move is to record it with Clipy and paste a hosted /video link with an inline preview. It is smaller, sharper, and never hits an attachment cap.