Free Automatic Slack Custom Emoji Resizer

Resize and compress a static or animated custom emoji for Slack entirely in your browser.

1 · Source

Choose one image

Browser only

Drop your image here

PNG, JPG, GIF, WebP, or APNG · up to 25 MB

Browse image

2 · Output

Automatic compliance

We keep reducing colors, quality, frames, and—only when allowed—pixel dimensions until the downloaded file passes.

Slack rules

  • Square image with a transparent background recommended
  • Under 128 KB
  • Animated GIFs can contain up to 50 frames
Slack custom emoji guidance

One file at a time. This resizer prepares an upload-ready image. It does not create packs, native apps, tray icons, cover images, or upload to Slack.