How to Make an Animated Emoji GIF Under 128 KB

Most animated emoji fail at upload for one reason: the file is too big. A GIF from a search engine is one to five megabytes, and Slack's cap is 128 KB, which is not a rounding error but forty times smaller. This guide is about making the file small from the start rather than shrinking it afterwards.

The caps, smallest first

• •Slack: 128 KB, 128 by 128 pixels, up to 50 frames. The tightest cap of any chat app.
• •Discord: 256 KB, shown at 128 by 128. Typing an animated emoji needs Nitro.
• •Kick: 512 KB for animated emotes at 128 by 128, in dedicated animated slots.
• •Microsoft Teams: 1 MB, resized to 128 by 128.
• •Twitch: 1 MB, up to 60 frames, in 112, 56 and 28 pixel versions, Affiliate or Partner only.

Where the bytes go

A GIF stores every frame as a full image with up to 256 colours. Three things decide the size: pixel count, frame count and colour count. Halving the width quarters the pixels; halving the frames halves the file; a smaller palette shrinks each frame. A 128 pixel loop with six frames and a modest palette lands between 30 and 60 KB, which is what the generator produces.

Make it small from the start

1. 1Describe one motion, not a scene: a wave, a bounce, a spin, a dance. A loop with one big movement reads at 22 pixels in a reaction; a scene does not.
2. 2Generate at 128 pixels with the Animated toggle. Six frames at 110 milliseconds each is a two-thirds-second loop that plays smoothly without strobing.
3. 3Check the size before uploading. Anything under 128 KB works everywhere on the list above; the generator's output is a fifth of that.
4. 4Keep the background transparent. Slack and Discord show emoji on dark themes, and an opaque box is the second most common reason a loop looks wrong.

If you already have a big GIF

• •Resize to 128 pixels first. That alone removes most of the bytes on anything larger.
• •Cut to the shortest loop that still reads. Eight to fifteen frames is plenty for a reaction.
• •Reduce the palette to 64 or 128 colours. Emoji have few colours to begin with, so this is nearly free.
• •If it still will not fit under 128 KB, remake it: a generated four-frame loop from a one-line description is faster than another compression round.