Add an Outline Around a PNG

follows the real silhouette · any width and colour · the sticker look · batch

The white border that makes a cut-out look like a sticker. The outline traces the actual edge of your image's opaque pixels — not a rectangle around it — so it works on logos, cut-out subjects and any shape with transparency.

How the outline is built

The image's alpha channel is filled with your outline colour to make a flat silhouette, and that silhouette is then stamped repeatedly around a circle of the radius you asked for. The union of all those offset copies is the shape grown outward by exactly that many pixels — a mathematical dilation — and the original image is drawn on top. The result follows every curve and notch of the real edge, with anti-aliasing preserved.

Because it grows outward, the canvas is expanded by the outline width on all four sides so nothing is clipped.

It needs a transparent source

This is the thing to check first if the result looks wrong. On an image with no transparency the silhouette is the entire rectangle, so you get a plain frame around the outside — which is what Border / frame does more directly. For the sticker effect the subject must already be cut out, with real transparency around it. Background removes a near-solid colour, and Transparency checker will tell you whether a file actually has an alpha channel at all.

Getting the look right

Sticker outlines are usually thicker than people expect — 8 to 20 px on a 1000 px image is the range that reads as intentional. Thinner than about 4 px and it looks like a rendering artefact rather than a design choice.

White is the classic choice because it separates the subject from any background. For a double outline, run the tool twice — white at 12 px, then black at 3 px on the result — which gives the outlined-sticker-with-a-keyline look. Adding Drop shadow afterwards completes the effect, and the shadow will correctly follow the new outlined silhouette.

One thing to know: very thin protrusions in the source — single-pixel antennae, wispy hair — get swallowed by the outline colour, because dilating by 8 px fills any gap narrower than 16 px. That's inherent to how outlining works, not a bug. Reduce the width if you're losing detail you need.

FAQ