Add a black outline to pixel art, or any colour you like. Drop a sprite with a transparent background, pick the thickness and placement, download the PNG. Everything runs in your browser.
Any PNG with a transparent background works: something you drew, a sprite from an asset pack, or an export from another tool. Paste from the clipboard or drag the file in.
Black is the default. AUTO matches the darkest tone already in the sprite. Outside adds new pixels around the silhouette, inside paints over the edge pixels instead. Every change re-runs live.
Save the PNG at native size, hold the compare button to check it against the original, or hand it to the app to animate or reskin it.
An outside outline is the safe default. It adds a ring of new pixels around the silhouette, so nothing in the original art is touched, and the sprite grows by the thickness on every side. The canvas grows with it, so the outline is never clipped at the edge.
An inside outline keeps the exact size, which matters when the sprite has to fit a fixed tile or an animation frame. The cost is that the outer ring of the art is painted over. It works well on chunky sprites with a solid fill, less well on thin limbs and single-pixel details. If the sprite already carries a dark outline that has gone uneven after scaling or editing, turn on the strip toggle: the tool recolours that ring from the pixels beside it, then draws a fresh, even one.
Grows the sprite. Original pixels untouched. Best for characters, items and anything without a size constraint.
Same size in, same size out. Edge pixels become the outline. Best for tiles, fixed-grid sprite sheets and UI icons.
Yes. It runs in your browser, nothing is uploaded, and there is no account, watermark or limit on how many sprites you outline.
The outline traces the edge between opaque pixels and transparent ones. On a flat image there is no edge to find, so it would only draw a box around the canvas. Remove the background first with the free background remover, then come back.
Outside adds a ring of new pixels around the sprite and grows the canvas to fit, so nothing in the original art is touched. Inside recolours the sprite's own edge pixels and keeps the size exactly. Use outside unless the dimensions are fixed.
On, the outline also fills the diagonal gaps at corners, so it wraps the shape in a solid unbroken line. Off, it only touches pixels straight above, below, left and right, which leaves small notches at diagonals. Some pixel artists prefer that open look on thin sprites.
A sprite sheet works as a single PNG as long as the frames are separated by transparent gaps: every frame gets its own outline. Pick inside if the frames sit on a fixed grid, so nothing shifts. For a GIF, convert it with GIF to sprite sheet first, outline the sheet, then rebuild it with sprite sheet to GIF.
Key out a solid background from any sprite, with halo cleanup. Do this first if your sprite is not transparent yet.
Scale a sprite by a whole number so every pixel stays a crisp square.
Snap any image to 2 to 64 colours, with optional dithering.
Open SpriteLab to keep building with your sprites.