Emojis in Slack can do a lot: trigger a workflow when you react (a reactji), signal you’ve finished an action item, or help you celebrate a co-worker! Finding the perfect emoji can clarify your tone and bring some fun to your conversations. And there are tons of emojis available in Slack.
But what if you want something more authentically you? Maybe you *must have* an amazing custom star emoji. Let’s dive in!
Step 1: Prepare your emoji
Just like configuration, we want to start with planning and design. There are a few considerations for custom emoji in Slack. Your emoji should fit the following parameters:
- File size: 128 kb
- Shape: Square
- Resolution: 128 pixels by 128 pixels
- File types: .jpg, .png, or .gif
- Accessibility tip: While you can create animated custom emojis, please remember that not everyone experiences .gifs in the same way. In fact, Slack users can deactivate animated emojis. Consider the accessibility impact to your workspace before adding animated emojis.
- Background: Transparent (preferred, but not required)
If you haven’t completed the steps above, take a moment to do so. I just grabbed a fresh cup of coffee, so I’m happy to wait. CAFFEINE. Also, look at this incredible star I made. Incredible.

Step 2: Add your emoji
Start from Slack desktop, click on any message you see, then select the emoji option. From here, you’ll see an Add Emoji button. All Slack users (except guests) in your workspace will have access to this button by default. Click Add Emoji.
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Now, it’s upload time
Select the file you created in Step 1. Upload that absolutely delightful visual manifestation of personal expression.
You’ll want to give your emoji a name that’s easy to use and somewhat unique. I named my custom emoji :jstar:.
Avoid names that may be used for standard emoji. Custom emoji that share a name with a standard emoji will be automatically deactivated in your workspace.
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Now that’s a cool star. Click Save.
Step 3: Emote, react, and enjoy!
Now that you’ve uploaded your custom emoji, you’ll be able to use it on desktop, web, or phone. And so can your team! You can access the emoji by typing the name (including the colon). You can also access it from the Reaction button on any Slack message.
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Can I delete custom emoji?
If you’re a workspace owner or admin, you can delete any custom emoji. If you aren’t a workspace owner or admin, you can only delete custom emoji you’ve added.
To delete the custom emoji, navigate to your workspace name, then Administration, and select Customize.
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This will open a new tab in your browser. Search for the emoji in question, and then click the red x to delete it.

Get creative!
Now that you’re equipped to add custom emoji to your workspace, it’s time to get creative—like exploring how a reactji can trigger workflows from Workflow Builder.
Custom emoji + Workflow Builder. It’s the :chefkiss: perfect combination.
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