How to use the Outline Generator
- Drop a sprite or sheet.
- Pick a color. 'Use darkest color' grabs the darkest color already in the sprite.
- Set thickness and choose outer, inner or both.
- Toggle corners: off gives the classic pixel-art outline with cut diagonals, on fills them.
- For sheets, keep 'outline each frame' on and check the grid, then download.
What you get
- PNG with the outline, canvas expanded so nothing clips
- Sheet with every frame outlined and grown by the same amount
Tips from making games with it
- Most hand-drawn pixel art uses outlines without diagonal corners at 1px. Turn corners on for 2px+ outlines or chunky UI icons.
- A dark tinted outline (deep purple or navy) usually looks better than pure black against varied backgrounds.
- An inner outline in a darker shade of the sprite's own colors is a quick way to add definition without changing the sprite size.
- When outlining a sheet, every frame grows by the thickness on each side. Update the frame size in your engine to match.
Use cases
- Making sprites readable on busy backgrounds
- Adding selection or hover outlines for items and units
- Outlining AI-generated sprites in a consistent style
- Building outlined UI icons
FAQ
What does the corners option do?
Off uses only up/down/left/right neighbours, which leaves the diagonal corners empty: the usual hand-drawn pixel-art look. On also uses diagonal neighbours, which fills those corners for a rounder, heavier outline.
Why did my image get bigger?
An outer outline needs room outside the sprite, so the canvas grows by the thickness on every side. Inner outlines keep the original size.
Will the outline bleed between frames on a sheet?
Not with 'outline each frame' on. Each frame is cut out, outlined and put back with extra room, so frames never touch.
Can I make a 'selected' highlight?
Yes. Use a bright color like yellow or white with an outer outline and keep it as a separate image to draw under or over the sprite at runtime.
Does it handle semi-transparent pixels?
Any pixel with alpha above zero counts as part of the sprite. Clean soft edges first with the Pixel Art Sharpener if you get a lumpy outline.