You can create custom emoji in Slack using the workspace settings, and they work across all channels and direct messages

Custom emoji in Slack are small images you upload to your workspace that appear alongside built-in emoji in the emoji picker. Once created, any member of your workspace can use them in messages, reactions, and status updates. You need workspace owner or admin permissions to create them, though some workspaces let all members upload custom emoji depending on the settings.

The process takes about two minutes: you upload an image file, give it a name, and it becomes available to everyone in your workspace immediately. The image must be a PNG, GIF, JPG, or WebP file under 128 KB in size.

Key Takeaways

  • Only workspace owners and admins can create custom emoji unless the workspace settings allow all members to do so.
  • Image files must be PNG, GIF, JPG, or WebP format and smaller than 128 KB to upload successfully.
  • Custom emoji appear in the emoji picker under a "Custom" section and can be used in messages and reactions just like built-in emoji.
  • You can delete or rename custom emoji from the same settings page where you created them.

How to upload a custom emoji from your computer

Open Slack in your web browser and go to your workspace name in the top left corner. Click the dropdown arrow next to it, then select "Settings & administration" and choose "Workspace settings." On the left sidebar, click "Emoji" to open the custom emoji management page.

Click the "Add Custom Emoji" button. A dialog box opens where you can either drag and drop an image file or click to browse your computer. Select your image file — it must be smaller than 128 KB. After the upload completes, Slack shows you a preview of how the emoji will appear. Type a name for the emoji in the text field below the preview. The name is what people type to use it (for example, if you name it "pizza-party", users type :pizza-party: to insert it). Click "Save Custom Emoji" and the emoji is now available to your entire workspace.

Image requirements and file size limits

Slack accepts PNG, GIF, JPG, and WebP image formats. The file must be smaller than 128 KB — if your image is too large, compress it before uploading. Square images work best because Slack displays emoji at a small size (usually 20 to 32 pixels), so any detail smaller than that will be hard to see.

If you have an image that is too large, you can use free online tools like TinyPNG or Squoosh to reduce the file size without much quality loss. For GIF emoji, keep in mind that animated GIF files tend to be larger, so you may need to compress them more aggressively to stay under the 128 KB limit.

Finding and using custom emoji in messages

Once a custom emoji is created, it appears in the emoji picker alongside all built-in emoji. Click the emoji icon in the message box (it looks like a smiley face) to open the picker. Look for the "Custom" section at the top or scroll through the list to find your emoji by name. Click it to insert it into your message.

You can also type the emoji name directly: if you named your emoji "celebration", type :celebration: in the message box and Slack will show it as a suggestion. Custom emoji work in reactions too — click the emoji icon next to any message and search for your custom emoji the same way.

Managing permissions for who can create emoji

By default, only workspace owners and admins can create custom emoji. If you want to let all members create them, go to "Workspace settings" and click "Emoji" again. Look for the option that says "Let workspace members add custom emoji" and toggle it on. This setting applies to everyone in the workspace.

If you turn on this setting, any member can create emoji, but workspace owners and admins can still delete emoji they think are inappropriate or off-brand. You can remove any custom emoji from the same "Emoji" settings page by clicking the trash icon next to it.

Renaming or deleting custom emoji

To rename a custom emoji, go back to "Workspace settings" and click "Emoji." Find the emoji you want to change in the list, click the pencil icon next to its name, type the new name, and click "Save." The emoji keeps the same image but now responds to the new name when people type it.

To delete an emoji, click the trash icon next to it on the same page. Once deleted, the emoji no longer appears in the picker and people cannot use it in new messages. Messages that already contain the deleted emoji will show a broken image icon instead.

Troubleshooting common upload problems

If your image won't upload, the most common reason is that the file is too large. Check that it is under 128 KB and in one of the supported formats (PNG, GIF, JPG, or WebP). If the file format is correct and the size is under the limit, try uploading it again — sometimes a temporary connection issue prevents the upload from completing.

If you see an error message saying you do not have permission to create emoji, you are not a workspace owner or admin, and the workspace settings do not allow all members to create them. Ask a workspace owner or admin to either create the emoji for you or change the permission settings.

Frequently Asked Questions

Can I use emoji from other websites or apps?

Yes. You can download or screenshot emoji from anywhere and upload them as custom emoji to Slack as long as you have the right to use them. Make sure the image is in a supported format and under 128 KB. Some emoji packs are free to use; others require permission or payment from the creator.

What happens to custom emoji if someone leaves the workspace?

Custom emoji stay in the workspace and remain available to everyone. They are not tied to the person who created them, so leaving the workspace does not delete them. Only workspace owners and admins can remove custom emoji.

Can I create animated emoji?

Yes, you can upload animated GIF files as custom emoji. Slack will play the animation when people use the emoji in messages and reactions. Keep in mind that animated GIFs are usually larger files, so you may need to compress them more to stay under the 128 KB limit.

How many custom emoji can I create?

Slack does not set a hard limit on the number of custom emoji you can create. However, very large numbers of emoji can make the emoji picker slower to load. Most workspaces stay under a few hundred custom emoji for performance reasons.

Can I see who created each custom emoji?

Slack does not display the creator's name next to custom emoji in the picker or settings. Only workspace owners and admins can see the full list of custom emoji and manage them, but the creator information is not shown publicly.