How to add custom emoji to Slack (desktop, bulk upload, naming rules)
2026-09-08
Custom emoji are unlimited on every Slack plan, and by default any member can add them. The whole process takes about a minute.
1. Prepare the file
- Format: GIF, PNG or JPG. Only GIF animates.
- Size: 128×128px or smaller, under 128KB. Large PNGs are resized automatically, but a GIF over 128KB is rejected or loses its animation.
- Every file on this site already meets these limits. Details are in Slack emoji size limits.
2. Open the emoji settings
Two ways:
A. From workspace settings
- Click the workspace name at the top left
- Tools & settings → Customize workspace
- In the browser page that opens, pick the Emoji tab
- Click Add Custom Emoji
B. From the message box
- Click the emoji icon in the message composer
- Click Add Emoji at the bottom of the picker
3. Upload and name
- Choose a file or drag it in. Drag several files at once to add them in bulk.
- Give it a name:
- lowercase letters, numbers,
-,_only - no spaces; the colons are added for you
- cannot reuse an existing name, including standard emoji
- lowercase letters, numbers,
- Save. It is available to the whole workspace immediately as
:name:.
The file name is pre-filled as the emoji name, so files from this site rarely need typing. Upload muyaho.gif and you get :muyaho:.
4. Aliases
To give an existing emoji a second name, click Add Alias on the same page. For example, make :thumbsup: also answer to :ok:.
5. Deleting and permissions
- Delete: hover the emoji on the Emoji tab and click the trash icon. Only the uploader and admins can do this.
- Restrict: admins can limit who may add emoji under Settings & permissions → Permissions → Custom emoji.
Common problems
| Symptom | Cause | Fix |
|---|---|---|
| “Image is too large” | GIF over 128KB | See shrinking GIFs |
| Name shown in red | uppercase, space or non-ASCII | use lowercase and _ |
| Animation frozen | over the limit, first frame saved only | reduce frames/colors and re-upload |
| No Add button | admins restricted the permission | ask an admin |
Ready-to-use emoji: browse Reactions and Work.
FAQ
Can I add custom emoji from the Slack mobile app?
No. Custom emoji can only be added from the desktop app or a browser. Mobile can use emoji that already exist.
What characters are allowed in an emoji name?
Lowercase letters, numbers, hyphens and underscores. No spaces or uppercase. Every emoji on this site already has a valid name.
Are custom emoji available on the free plan?
Yes. Custom emoji are unlimited on every Slack plan, including Free.
Who can delete a custom emoji?
The person who added it and workspace admins.