Slack Custom Emoji Resizer

What matters

Slack Custom Emoji dimensions at a glance

Slack custom emoji at 128×128 are displayed at around 22px in messages. They're an important part of workspace culture and communication shorthand.

Custom emoji streamline communication and build team culture. Well-designed emoji get used constantly in reactions and messages.

Detailed designs become unreadable blobs in chat. Files over 128KB get rejected. Poor transparency creates ugly boxes around emoji.

Best practices

Use the crop intentionally

• Design for 22px readability — that's the actual message display size.
• Use transparent backgrounds for seamless integration.
• Simple, high-contrast designs with bold lines work best.