Sticker & Emoji Pack

Sticker & Emoji Pack turns one cutout into a set of outlined stickers and emoji with transparent backgrounds, at the sizes each chat platform documents, and gives them to you as one ZIP. It runs in your browser and your image is never uploaded.

What it makes, and where each rule comes from

Every rule below was read from the platform's own documentation on 23 September 2026.

Two of those need saying plainly. Slack's page asks for square images under 128 KB and names no pixel size, so the 128 pixel Slack emoji is our choice, not Slack's rule. Telegram's pages give exact dimensions but no file-size limit for static stickers or emoji, so this page does not enforce one for them.

How a sticker is made

1. Crop to the subject. Every pixel more than 2 percent opaque counts, so a soft edge is kept.
2. Fit it into the size. The subject is scaled to fill the frame with a small margin, keeping its shape, and centred. For the Telegram sticker the longer side is exactly 512 and the other side is only as large as your subject needs.
3. Resample carefully. Colour is blended together with transparency, so no dark fringe appears along the edge, which is what happens when fully transparent pixels are averaged in as black.
4. Add the outline. Every pixel within the outline width of your cutout's silhouette gets the outline colour, and the outline sits underneath your cutout. Because it is drawn a fixed distance out in every direction, its corners come out round.
5. Encode a PNG and check it against the platform's limit.

The outline width is a fraction of each sticker's size, with a floor of one pixel, so a thin outline looks the same at 32 pixels and at 512. It wraps everything at least a tenth opaque, which is what lets a glass bottle or a soft edge sit on the outline instead of floating beside it.

Nothing in that list is a model. Nothing is trained, nothing is generated, and nothing is downloaded.

File-size limits

Every file is measured after it is encoded. If one is over its platform's limit, the page reduces the number of colours and encodes it again, and if it still does not fit, it says so beside that file rather than handing you something the platform will refuse. At these sizes that is rare: a 320 by 320 image is 400 KiB before any compression, under Discord's 512 KiB sticker limit, and the smaller sizes are further inside theirs.

Starting from a photo

A sticker needs a cutout, because the outline follows the subject's edge and an ordinary photo has none. If you choose a photo with an opaque background, the page offers to remove the background first. That runs the site's Fast background remover on your device and downloads its model, about 45 MB, the first time; after that your browser keeps it. If no earlier tool in this browser has loaded the shared ONNX Runtime engine the model runs on, that first run also fetches it, up to about 24 MB, once.

What to expect

• Small gaps fill in. Any gap narrower than twice the outline, like the inside of a mug handle, closes up. That is the die-cut sticker look. Use a thinner outline, or none, to keep it open.
• Small cutouts get enlarged. If your cutout is smaller than a sticker size, it is scaled up to fill it and looks softer there. The page lists which sizes that happened to.
• Still images only. No animated stickers, GIFs or WebP.
• There is no image-editor version yet. The editor keeps your photo and your selection separately and draws the subject through the selection, so an outlined sticker placed there would be clipped back to the subject. Make the cutout in the editor or the background remover, then bring the transparent PNG here.