LumiBear Studio
English

Slack emoji maker Free

Turn a video or GIF into an animated Slack emoji — square, under 128KB, 50 frames at most. Right in your browser, nothing is uploaded. Free.

How to make a Slack emoji

  1. Drop a video or GIF in, or click to choose one.
  2. Pick the moment you want (a few seconds is plenty) and drag the square over the part to keep.
  3. Press "Make emoji", save it, then add it as a custom emoji in Slack (desktop app or browser).

What it can do

No upload

Everything happens in this browser. No sign-up.

Square, automatically

Drag the square to choose what stays, or fit the whole picture with clear edges.

Under 128KB

It lowers colors, smoothness and size until the file fits Slack's emoji limit.

Within 50 frames

Longer clips get fewer frames per second, so the GIF stays within Slack's 50-frame limit.

Videos or GIFs

Start from an MP4, MOV or WebM clip or an existing GIF — transparent GIFs stay transparent.

GIF

Images

Video

PDF

Questions

What are Slack's emoji rules?

Slack's help center (checked November 2026) says square images under 128KB work best, in JPG, PNG or GIF, and GIFs can have up to 50 frames.

Why can't I add emoji?

Workspace owners can limit who adds custom emoji, so ask an admin if the option is missing. Slack also says custom emoji can't be added from its Android app — use a computer or a browser.

Is my file uploaded?

No. The video or GIF is read and turned into an emoji only inside this browser. This page never sends it anywhere.

What if my clip is long?

Slack allows 50 frames, so a 5-second clip gets about 10 frames per second. Shorter clips stay smoother — 2 to 3 seconds is a good length.

Is this made by Slack?

No. LumiBear is not affiliated with Slack. The Slack name belongs to its owner; this page just makes GIFs that fit Slack's emoji rules.