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Slack Custom Emoji Generator
Slack Custom Emoji Generator builds 128×128 px, ≤128 KB custom emoji you can upload to Slack as-is. Pick "Text" mode or "Image" mode depending on the source.
Preset phrases
Weight
Horizontal align
Vertical align
Text size
Per line max = honors line breaks, no auto-wrap. Uniform = same size across lines, wraps when needed.
Animation output
Preview
How it looks in Slack (22px / 44px × Light / Dark)
Everything runs entirely in your browser and is never sent to a server.
Slack limits: 128 × 128 px recommended ・ up to 128 KB ・ PNG / GIF / JPG supported.
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About Slack Custom Emoji Generator
Slack Custom Emoji Generator builds 128×128 px, ≤128 KB custom emoji you can upload to Slack as-is. Pick "Text" mode or "Image" mode depending on the source.
Text mode includes Japanese and Latin fonts, text/background color, outline, vertical and horizontal alignment, plus three GIF animations — "Blink", "Marquee", and "Zoom". Image mode accepts JPG / PNG / GIF and rescales them to 128×128 (GIF animation is preserved).
All text and images are processed entirely in your browser — nothing is uploaded to a server. Even custom emoji with inside jokes are safe to make. Runs entirely in your browser.
How to use
- Choose "Text" or "Image" mode.
- In text mode, enter the phrase and tune font, text/background color, outline, and alignment. Preset phrases ("Thanks", "FYI", etc.) are also one click away.
- In image mode, pick or drop a JPG / PNG / GIF and adjust cropping and position.
- Choose "Blink", "Marquee", or "Zoom" to export as an animated GIF.
- Preview, then click "Download" to save a PNG or GIF optimized to 128×128 / ≤128 KB.
- Upload it from Slack's "Add custom emoji" screen.
Use cases
- Operators energizing reactions on a work Slack — turn frequent phrases ("Thanks", "FYI", "On it") into emoji.
- Adding team member portraits, logos, or mascots as 128×128 Slack emoji.
- PR teams batch-generating campaign or event emoji for distribution.
- Community owners adding animated GIF emoji to liven up reactions.
- Reusing 128×128-ish emoji on Discord and Microsoft Teams, which have similar specs.
Notes
- Output is automatically tuned to Slack's spec: 128×128 px and ≤128 KB.
- Image input must be JPG / PNG / GIF and ≤5 MB; anything larger errors.
- Animated text exports as GIF; static text exports as PNG. Turning off the background gives you a transparent PNG.
- Slack plays back animated GIFs as reactions, but some clients (e.g., Microsoft Teams) may show only a still frame.
- Fonts come from a curated set of Google Fonts (Japanese and Latin).