Animated emoji for Slack
Turn a clip into a square Slack emoji: under 128 KB and at most 50 frames.
Drop a video, or choose a file
MP4, MOV, WebM or MKV. Short clips work best.
Your file never leaves your device
Slack limits
| What | Official limit | Source |
|---|---|---|
| Custom emoji | Square, under 128 KB works best; GIFs up to 50 frames | slack.com |
Limits verified Oct 2, 2026 against official sources.
Report an outdated limitWhy files fail on Slack
Slack says custom emoji work best square and under 128 KB, and GIF emoji can have at most 50 frames. Bigger ones fail or look broken.
What this preset does
This preset crops to a centered square, keeps up to 50 frames and lowers the frame rate until the GIF is under 128 KB.
Questions
- What size should a Slack emoji be?
- Square and under 128 KB works best, according to Slack. Slack doesn't publish a pixel size; 128 × 128 is a safe choice.
- How many frames can a Slack GIF emoji have?
- Up to 50.
- Can I use a transparent background?
- Slack recommends transparent backgrounds for still emoji. Video clips have no transparency, so GIFs from video are opaque.