Discord Emoji Maker

Custom emoji are tiny: Discord shows them at 22 pixels inside a message and 48 pixels when sent alone, and Discord recommends uploading a 128 × 128 square; Slack suggests square images under 128 KB. Big photos with empty margins turn into an unreadable dot at that size. This maker trims the empty edges, fits or crops the picture into a 128 × 128 PNG with a transparent background, suggests a valid emoji name, and shows how it will look in chat on dark and light themes.

How to use this tool

1. Choose one or more images (a PNG with a transparent background works best).
2. Pick Discord or Slack and leave "Trim empty edges" on so the subject fills the square.
3. Keep "Whole image" with a little padding, or crop to fill and frame it with zoom and position.
4. Optionally cut it to a circle or rounded square, or add a background colour.
5. Download the PNG and upload it under Server Settings → Emoji (Discord) or Customize workspace → Emoji (Slack).

Formula

content box = 128 × (1 − 2 × padding) · scale = min(box ÷ width, box ÷ height)

Trimming finds the smallest rectangle containing pixels that are not transparent; for images without transparency it uses pixels that differ from the top-left corner colour by more than 12 levels. "Crop to fill" uses the larger of the two ratios, times the zoom. Names keep letters, digits and underscores, 2–32 characters.

Example

A 600 × 400 logo with a 100 px empty margin on every side is trimmed to its 400 × 200 content. With 4% padding the box is 128 × 0.92 = 117.8 px, so the logo is drawn 117.8 × 58.9 px, centred, instead of 76.8 × 51.2 px without trimming. A 128 × 128 PNG is under about 66 KB even uncompressed, well inside Slack's suggested 128 KB and Discord's 256 KB limit.