Add a Sticker-Style Outline to a Cutout Image
Add an outline of any width and color that follows the edge of a transparent PNG. Double borders, a drop shadow, and hole filling are supported, and the result is saved as a transparent PNG. If your image still has a background, cut it out first with the Image Background Remover. Everything runs in your browser and nothing is uploaded.
🔒 Runs in your browser · Your data is never sent to a server
Drag and drop a cutout image (such as a transparent PNG) here, or pick one with the button.
Preview (the checkerboard is transparent)
How to use
- Drag and drop a cutout PNG with a transparent background into the box, or pick one with the button.
- Set the "Outline width" and "Outline color". The preview shows the result.
- If you like, add a double border with "Outer border width", a shadow with "Shadow opacity", and fill ring-shaped gaps with "Fill inner holes".
- Click "Download transparent PNG" to save it.
Notes
- The outline is drawn around the non-transparent part of the image (pixels with more than a small alpha value). An image without transparency, such as a JPEG, gets one rectangular outline around the whole picture.
- The output grows by the outline width on all four sides, and by the shadow offset as well when a shadow is on.
- Images with a long side over 2000 px are scaled down before the outline is added, to keep processing light.
- "Fill inner holes" only fills transparent areas that do not touch the image border. Notches that open to the edge stay open.
Glossary
Alpha channel
Data that stores the transparency of each pixel. PNG and WebP support it, so the background can be saved as transparent. JPEG does not.
Distance transform
A calculation of how far each pixel is from the nearest point of a shape. This tool paints every pixel whose distance is within the outline width, which gives a smooth, round outline.
FAQ
What happens if I add an outline to a JPEG with a white background?
A JPEG has no transparent area, so the whole picture counts as one rectangle and the outline follows its rectangular edge. To follow the subject instead, first make the background transparent with the Image Background Remover and use the resulting PNG.
Are the outline corners rounded?
Yes. The outline is grown with a circular kernel (a distance transform), so corners come out rounded and the thickness is the same in every direction. The larger the width, the more thin spikes and sharp corners are smoothed into a round shape.
The inside of a ring or a letter stays transparent.
If the outline width is smaller than the hole, the inside stays transparent. Turn on "Fill inner holes" to paint every transparent area that does not touch the image border with the outline color.
Can it handle large images?
Images with a long side over 2000 px are scaled down to 2000 px, keeping the aspect ratio, before processing, and the outline width is measured in pixels of the scaled image. If you need a high-resolution result, resize the image to the size you need beforehand.
Is my image uploaded to a server?
No. Everything from the outline calculation to saving the file happens in your browser, and the image is never sent anywhere.
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