Slack Emoji GIF

Drop the GIF into the tool above. It center-crops the GIF to a square, scales it to 128 px, and compresses it under 128 KB — the three things Slack needs — then you download the result and add it in Slack under Add emoji. Everything runs in your browser; the GIF is never uploaded to a server. No separate converter or sign-up needed.

Short loops with one clear subject. Slack displays emoji at roughly 22 px, so fine detail and text disappear — a single bold motion (a thumbs-up, a head nod, a reaction face) reads far better than a busy clip. Already-square or center-weighted GIFs survive the square crop without losing the subject. Long, wide, or high-color GIFs are the ones that fail the 128 KB / square / 50-frame limits, so trim to the key 1–2 seconds before compressing.

Slack requires square images under 128 KB, in JPG, PNG, or GIF format, and animated GIFs can include up to 50 frames. (128×128 px is the widely used standard size — Slack states “square” without an official pixel maximum.) Anything over 128 KB is rejected at upload. Workspace admins can sometimes restrict emoji creation, but the file rules are workspace-independent.

Slack drops animation if total frames + colors are too heavy after their re-encode pass. Try the "Allow shorter loop" toggle (default on), or open Advanced and reduce colors. Short, simple loops survive Slack's pipeline more reliably.

The source GIF may have too many frames, too many colors, or dimensions that need a harsh crop. Keep the loop short, use the 128×128 square output, and allow the compressor to trim trailing frames when needed.

No — Slack requires square emoji. We always center-crop to square before scaling. The "Square edge" input controls the single edge length used for both width and height.

Discord server emoji is a stricter emoji workflow than ordinary uploads. Use /compress-gif-to-256kb for a 256KB byte target today, or /reduce-gif-size when another platform gives you a different custom limit.