Sticker Maker
Add a pixel-perfect outline to any sprite or image — great for Discord stickers and game assets. Works best with transparent PNGs.
Drop a PNG with transparency here
Free Sprite Outline Generator
Station255's Sticker Maker adds a smooth pixel-perfect circular outline to any image, producing the classic "sticker border" effect used in Discord stickers, Telegram emotes, game sprite outlines, and stream overlays. The algorithm expands the image's opaque region outward by the specified pixel thickness using a circular sampling kernel, then draws the original on top with a transparent background. No server involved — fully Canvas API.
How the outline algorithm works
The tool creates a binary mask of all non-transparent pixels, then draws that mask at every offset within a disk of radius = thickness pixels. All non-transparent pixels in the expanded mask are recolored to the chosen outline color. The original image is then composited on top, leaving a clean colored border around every sprite edge.
Use cases
Discord custom stickers (max 500KB PNG), Telegram sticker packs, Twitch overlay elements, pixel-art sprite outline for game UI, README badges, and social media avatar frames.
FAQ
My image has no transparency — will it work?
Yes, but the outline will follow the image's rectangular boundary. For best results use a PNG where the sprite has a transparent background.
Can I make the outline thicker than 12px?
12px is the current maximum. Larger values make the outline loop slow — if needed, upscale your sprite first with Pixel Upscaler, then add the outline.