Slack Emoji Size Limit: Dimensions, File Size and GIF Frames

The short answer

Slack accepts JPG, PNG and GIF emoji. Square images under 128 KB work best, and animated GIFs can include up to 50 frames. 128×128 pixels is the usual target.

Why your emoji won't upload

• The file is over 128 KB. Animated GIFs hit this most often.
• The GIF has more than 50 frames.
• The image isn't square, so it gets letterboxed or squashed.

Fix it in one step

Our free Slack emoji resizer crops your image square, resizes it to 128×128, caps it at 50 frames and compresses it under 128 KB. Need a new emoji from scratch? Try the AI Slack emoji maker.

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