Round the corners of any image
Give any image soft, rounded corners — ideal for cards, avatars, thumbnails and UI mockups. Pick the radius with a slider and download a PNG whose corners are fully transparent, so it sits cleanly on any background.
How it works
The image is drawn onto a local <canvas> that is clipped to a rounded
rectangle. The corner radius is calculated as:
radius = chosen % × shorter side of the image (capped at half the shorter side)Because the radius is a percentage of the shorter side, the rounding looks proportional whether the image is a small thumbnail or a large photo. The cut-away corners are left transparent, which is why the file is exported as a PNG.
Worked example
A 800 × 600 image with a 12% radius:
- Shorter side: 600 px
- Corner radius: 12% × 600 = 72 px
- Output size: 800 × 600 PNG with four 72 px rounded, transparent corners
Common uses
- Rounded thumbnails and cover images for cards and grids.
- Avatars and profile pictures that need a soft, modern look.
- UI and app-store screenshots that match a rounded design language.
It all runs on a local canvas, so your images are never uploaded.