Slack emoji too big? Get it under 128 KB

Slack checks two things on an animated emoji: the weight, under 128 KB, and the frame count, 50 at most. This page makes a square GIF that passes both.

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Your clip will show up here

Drop a video or GIF

MP4, MOV, WebM, GIF and more

Size – Dimensions – Output –
Download

Output

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Drag the frame over the picture to choose what ends up in the emoji. Grab a corner to zoom in on a face or a detail.

Pick a file to start.

Slack's two rules

Slack's help page says it plainly: images for custom emoji should be square and under 128 KB, and a GIF can include up to 50 frames. Break either one and the upload stops. Most GIFs that fail here are fine in pixels and fail on frames: a three-second clip at 25 frames a second is 75 frames before the weight is even counted.

How this page gets it through

Drop a GIF or a video clip in the box above. The frame rate is set from the length of your trim so the total never passes 50 frames, the picture is cut to a square and rendered at 128×128, and if the file weighs more than 128 KB the colour count comes down in steps until it does not. Nothing is uploaded; the work runs inside this browser tab.

Keep the trim short. Two seconds gives you 25 frames a second and a fluid loop; four seconds leaves 12 frames a second, which looks choppier.

Adding the emoji

  1. Open the emoji picker in any message box and choose Add emoji, or go to Customize Workspace in the menu.
  2. Upload the GIF from this page and give it a name. The name becomes its shortcode.
  3. Workspace admins can restrict who adds emoji, so if the option is missing, ask one.

For framing tips and ideas, see the Slack emoji maker. The size limits table has the rules for other platforms.

Questions

My GIF is only 90 KB and Slack still refuses it

Count the frames. A light GIF with 80 frames fails on the second rule. Run it through this page and the frame rate is adjusted to fit under 50.

Does a transparent background matter?

Slack recommends it because the emoji sits on light and dark themes alike. A clip from a video has no transparency; that is accepted, it just shows as a small square.