How to Add Custom Emoji to Slack (Desktop and iPhone)

To add a custom emoji to Slack on desktop, click the smiley face in the message box, click Add Emoji, click Upload Image, type a name, and click Save. Everyone in the workspace can then use it as :name:, and it shows up under the Slack icon in the emoji picker. The dialog asks for "square images under 128KB", but that is advice, not a limit. On 1 October 2026 a 1000 x 1000 PNG of 1.9 MB uploaded fine, because Slack shrinks every image to 128 x 128 pixels. The limit that does stop you applies to animated GIFs: the file must still be small after that shrink.

We ran every upload on this page in our own Slack workspace (Free plan, signed in as the workspace owner) through the Add emoji dialog and the same emoji.add call the dialog makes, then removed the test emoji.

How to add a custom emoji to Slack on desktop

• In any conversation, click the smiley face in the message box.
• Click Add Emoji at the bottom of the emoji picker.
• On the Custom emoji tab, click Upload Image and choose a PNG, JPG or GIF.
• Under Give it a name, type the code people will use, such as shipit. Slack fills in the file name and turns spaces into hyphens.
• Click Save.

The emoji works right away in messages, reactions and your status. On an iPhone or iPad, tap the smiley face in the message box, enter a name, then tap Add custom emoji and pick the image. Slack's Android app has no option to add custom emoji, so use a computer or a browser.

What the upload accepts: our test results

We sent each file and name below to Slack and wrote down the answer. The error codes are what emoji.add returned; the dialog shows the same refusal as a plain sentence.

What we uploaded	Result
PNG, 1000 x 1000 px, 1.9 MB	Added. Slack stored it as a 128 x 128 PNG of 23 KB
GIF, 128 x 128 px, 60 frames, 29 KB	Added, all 60 frames kept
GIF, 128 x 128 px, 40 frames of noise, 924 KB	Refused: resized_but_still_too_large
Name SG1001-Upper	Refused: error_lower_case_names_only
Name sg1001 space	Refused: error_bad_name_i18n
Name thumbsup	Refused: error_name_taken_i18n (a built-in emoji)
A name we had already used	Refused: error_name_taken



Three things follow from the table:

• • Size only matters for GIFs. A still image of any size we tried was shrunk and accepted. A GIF is shrunk too, and is refused if the result is still too large. Our 60-frame GIF with flat colours passed at 29 KB; the 40-frame GIF full of random pixels did not. Fewer colours and fewer frames make a GIF smaller.
• • The 50-frame rule did not hold. Slack's help center says animated emoji can have up to 50 frames. Our 60-frame GIF kept all 60, and on 30 September a 150-frame GIF was accepted too.
• • Names are lowercase. Letters, numbers, hyphens and underscores work. Capitals, spaces and most punctuation are refused, and so is the name of any standard emoji.

To shrink a GIF, crop it or cut frames before you upload; our free Slack emoji resizer does both in the browser, and Slack GIF size limit has the numbers. To make the image in the first place, see the next section.

Make a Slack emoji from a picture

To make a Slack emoji from a picture, crop the photo to a square around one face, logo or object, scale it to 128 x 128 pixels, and save it as a PNG. Remove the background if it is a plain color, or it shows as a white square in dark mode. Then upload it with Add Emoji as above.



Our free Slack emoji maker does it in the browser, and the picture never leaves your computer:

• Keep Image to emoji selected, then drop in, choose or paste a PNG, JPG, GIF or WebP. A screenshot on your clipboard pastes straight in.
• Leave Crop to square on and frame the subject with Zoom, Left/right and Up/down.
• Tick Remove background if the subject sits on a plain color.
• Check the previews at 16, 22 and 32 pixels. An emoji shows at about 22 pixels in a message, so if the subject is hard to see there, zoom in more.
• Optional: pick an effect such as intensifies or party to make it an animated GIF.
• Download the file. The tool suggests an emoji name.

From the command line, ImageMagick fills a 128 x 128 square from the center in one line, and macOS has sips built in. We ran both on 7 October 2026 on the parrot photo that ships with macOS, a 512 x 512 PNG of 417 KB:

magick photo.png -resize 128x128^ -gravity center -extent 128x128 -strip emoji.png
sips -c 440 440 photo.png --out crop.png
sips -z 128 128 crop.png --out emoji-sips.png
ls -l emoji.png emoji-sips.png

-rw-r--r--@ 1 sieunpark  staff  35298 Oct  7 10:09 emoji-sips.png
-rw-r--r--@ 1 sieunpark  staff  30528 Oct  7 10:09 emoji.png

That is 30.5 KB and 35.3 KB, both 128 x 128. Slack would have taken the 417 KB original too, since it shrinks still images itself, but cropping first decides what stays in the frame. At 22 pixels the parrot's red head and yellow beak still read and its eye does not: color and shape survive, detail does not.

Picture	How to crop	Tip
Face or selfie	Head only, chin to hair	A big expression reads better than a neutral one
Logo	The symbol, not the full wordmark	Thin lines vanish at 22 px, so thicken them
Pet photo	Face, ears to chin	Keep a busy background if removing it eats the fur
Screenshot	One icon, word or number	Only large text survives

A picture of a coworker needs their OK first, because everyone in the workspace can use a custom emoji once it is added. To animate a picture or draw a GIF from a description, see make your own Slack GIF.

Why you can't add emoji to Slack

If the Add Emoji button is missing or greyed out, the cause is a workspace setting, not your file:

If the button works but Save fails, match the message to the table above: "a bit too big, even after resizing" means the GIF is too large, and a name error means the name is taken or has capitals or spaces. A white square around the emoji in dark mode means the image has no transparent background; how to make an emoji background transparent for Slack fixes that.

Aliases, emoji packs and bulk uploads

An alias is a second name for an emoji that already exists, such as :yes: for :+1:. Open https://<your-workspace>.slack.com/customize/emoji in a browser, click Add Alias, pick the emoji and type the new name. The same page has Add Custom Emoji and the list of every custom emoji in the workspace.

Emoji packs are sets Slack offers ready-made. In the Add emoji dialog, open the Emoji packs tab and click Add Pack; Slack emoji packs shows what is in them. The dialog takes one file at a time, so for a folder of your own images use the Slack emoji bulk upload tool, which fixes each name and adds them from a Slack browser tab. Apps cannot add emoji through the API outside Enterprise plans; our emoji API test shows the errors.

How to remove a custom emoji

On the same /customize/emoji page, find the emoji and click the delete icon. Members can delete only the emoji they added; owners and admins can delete any. More in how to delete a Slack emoji.

FAQ

Can I use another company's custom emoji? In a Slack Connect channel or DM, you can right-click another organization's custom emoji to add it to your workspace.

Can I rename a custom emoji? No. Add it again under the new name, or add an alias, then delete the old one.

Why does my animated emoji not move? Slack shows animated emoji frozen for anyone who turned off animations in Preferences, Accessibility. Slack GIF not playing covers the other causes.

Do custom emoji work as a status? Yes. Any custom emoji in the workspace can be your status emoji.