Slack Emoji Resizer

Resize any image to the perfect 128×128 Slack emoji size and keep it under the 128KB limit — instantly, free, and 100% private.

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📤 Click to upload or drag & drop an image here

PNG, JPG, GIF, or WebP — your file never leaves your device
128 × 128 preview

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How to resize an image for a Slack emoji

  1. Click the upload box above (or drag your image onto it).
  2. The tool instantly resizes it to 128×128 pixels.
  3. Click Download and add it under your Slack workspace's custom emoji settings.

What size is a Slack emoji?

Slack custom emojis should be 128×128 pixels and under 128KB. This tool resizes and compresses any image to fit.

Slack image size cheat sheet

AssetRecommended size
Custom emoji128 × 128 px
Workspace icon512 × 512 px

Frequently asked questions

Is this tool free?

Yes — completely free, no signup, no watermark. Everything runs in your browser, so your images are never uploaded to any server.