YilunaSlack stickers
Slack emoji maker: animated emotes that fit under 128KB
Slack caps every custom emoji at 128KB and renders it at 128×128 — a tight budget for animation. The exporter renders your motion preset as a 128×128 GIF and steps palette, frame rate and dimensions down until the file fits, so the upload form never bounces it.
Static emoji export in the same click as a transparent 128×128 PNG, and the live preview loops exactly the way Slack does in chat.
Make a Slack sticker nowThe exact Slack spec
| File | Format | Size | Limit |
|---|---|---|---|
| Animated emoji GIF | GIF | 128×128 | 128KB |
| Static emoji PNG | PNG | 128×128 | 128KB |
How to publish on Slack
- Make the emote. Start from a template, upload a reaction image, or AI-generate a character. Bold shapes read best at emoji size.
- Animate it. Bob, jelly, wiggle and wave presets cover the classic emote motions — the character moves, the background stays still.
- Add it to your workspace. Slack desktop → workspace name → Customize workspace → Emoji → Add custom emoji. The GIF is already under 128KB so it just works. Admins can restrict who may add emoji.
Questions
What is the Slack emoji size limit?
128KB per emoji, displayed at 128×128. GIF, PNG and JPG are accepted; a transparent GIF or PNG looks native in both light and dark themes.
Why does Slack reject my animated emoji?
Almost always file size — most editors export animated GIFs far above 128KB. This exporter compresses in passes (palette, frame rate, dimensions) until the file clears the limit.
Can everyone in the workspace use my emoji?
Yes. Once uploaded, a custom emoji is available to the whole workspace, and animated ones play for everyone. Workspace admins can limit who is allowed to add them.