Round the Corners of an Image or Crop It to a Circle
Soften square corners by a percentage, or switch to circle mode for a perfectly round avatar.
About the Rounded Corner Image Tool
The corner radius is expressed as a percentage rather than a pixel value, running from 1 to 50 and starting at 12. That choice matters for consistency: because the radius is calculated from the shorter side of each image, the same setting produces visually matching corners across pictures of different sizes, which a fixed pixel radius cannot do. A tick box switches to circle mode, which crops the image to a centred square first and then rounds it fully, producing the round avatar most profile systems expect.
Output is always PNG, and that is not a limitation so much as a requirement — the area outside a rounded corner has to be transparent, and PNG is the format that can store it. There is consequently no quality slider to set. Several images can be processed together, and the rounding happens in your browser, which suits client photography that has not been published.
Key Features
- Radius as a percentage: Values from 1 to 50 are measured against the shorter side, so a batch of mixed sizes ends up visually consistent.
- Circle mode: One tick box crops to a centred square and rounds it completely for a round profile image.
- Transparent corners: The area outside the curve is genuinely transparent rather than filled with a background colour.
- PNG output guaranteed: The format is fixed to the one that can carry transparency, so there is no way to accidentally export a version with white corners.
- Batch consistency: Apply the same radius across a set so every thumbnail in a grid matches.
How to Use the Rounded Corner Image Tool
- Add the images you want to round.
- Set the radius percentage, or tick circle mode for a fully round result.
- Check the preview — the corners show as transparent.
- Export the PNG, or take the batch as a ZIP.
How It Works
A rounded rectangle path is created on the output canvas, the context is clipped to that path, and the source image is drawn inside it so anything beyond the curve is discarded. In circle mode the shorter dimension is measured first, offsets are calculated to take a centred square, and the radius becomes half the width. The result is encoded as PNG so the clipped region stays transparent. On browsers too old to support the rounded-rectangle path method there is a circular fallback, which means a very outdated browser may return a circle where you asked for soft corners — any current version of Chrome, Edge, Firefox or Safari behaves as expected.
When You Need It
A wedding photographer building a private client gallery wants circular thumbnails for the guest-facing index while keeping the full frames square. Circle mode produces those in one pass across a hundred images. The photographs are covered by a client contract and often include children and family members who have not consented to appearing anywhere public, so routing them through a free avatar site would breach the agreement the couple signed. Membership organisations producing directory headshots and app teams generating rounded tiles use the same crop for interface reasons.