Image Rounded Corners
Round image corners or crop to a perfect circle for avatars. Radius in pixels or percent, transparent or solid background. PNG with alpha. Runs in your browser.
Sharp square corners were the digital design default through the early 2000s, but Apple's iOS 7 in 2013 reset the visual standard: rounded rectangles everywhere, with the superellipse (squircle) shape for app icons. The shift spread through every platform — Material Design, Windows 10, and macOS Big Sur all adopted softer corners as the modern default. Today, any avatar, product card thumbnail, or app icon with unmodified square corners looks visually dated against its neighbors.
The technical mechanism is a clipping path on a canvas element. A rounded-rectangle path — matching the model behind CSS border-radius — clips the image; pixels outside the path become transparent in the exported PNG. The maximum meaningful radius is exactly half the shorter side: the arcs would overlap beyond that point, and at exactly half, the result collapses into a perfect inscribed circle — which is what the “Full circle” option delivers for profile photos, team page headshots, and chat app avatars.
Rectangular images inscribe the circle from the shorter side, which clips the longer edges. Crop to square first for the cleanest circular avatar, then round here. Output is always a transparent PNG — compatible with dark mode, light mode, and any background color without further modification.
Drop an image to round its corners
PNG output preserves transparency — never uploaded
How to round image corners online
Drop your image. Drag the radius slider — pixels for exact control, percent for relative sizing across different images. Check Full circle to crop a square image to a perfect avatar. Pick a transparent background (PNG alpha) or a solid color for the corners. The preview updates as you adjust. Click Download PNG.
Why a local corner-rounder matters
Rounded corners are usually applied to brand assets, app icons, avatars, and marketing visuals — material that often sits behind logins or in pre-launch state. Uploading those to a third-party tool is a needless leak. ToolChop runs entirely in your browser, and the output is a clean transparent PNG with no watermark or signup wall.
Pixels vs percent — when each matters
Pixels are exact: 40px corners are 40px corners regardless of image size, which is what icon and avatar specs typically demand. Percent is relative to the shorter side, so the same percent value produces visually-similar corners across different image sizes — useful when you are rounding several images for a consistent look across a deck or page.
What you can do
- Corner radius in pixels or percentage of the shorter side
- Full-circle mode for perfect avatar crops
- Transparent or solid-color background for the corners
- Live preview as you adjust
- PNG output preserves alpha channel
Frequently asked questions
How do I round the corners of an image online for free?
Drop your image. Drag the corner-radius slider (px or %), or check Full circle for a perfect circular avatar crop. Pick a transparent background or a solid color. Click Download PNG. No account, no upload, no daily limit.
Does ToolChop upload my image?
No. The image is decoded into a canvas in your browser, clipped to a rounded path, and exported as a PNG with alpha — all locally. The file never leaves your device.
Why is the privacy story for a corner-rounder important?
Rounded corners are usually applied to brand assets, app icons, avatars, marketing visuals — material that often sits behind logins or in pre-launch state. Uploading those to a third-party tool is a needless leak. ToolChop runs entirely in your browser.
What does Transparent background mean in practice?
The PNG you download has alpha channel transparency in the rounded-off corners. When placed on any background (a website, a slide deck, a social profile), the underlying surface shows through. This is how proper avatars look on dark mode and light mode without modification.
When should I pick a solid background color instead of transparent?
When the final use is a system that does not handle PNG transparency well — older versions of some chat apps, certain print workflows, raster output for legacy software. Pick the color that matches the destination background so the corners are visually invisible.
What does Full circle do?
Crops the image to a perfect circle inscribed inside the image's shorter side. If your image is square, that produces a perfect avatar (the entire image's diameter). If your image is rectangular, the circle uses the shorter side as diameter — for best results, crop to a square first with our Image Cropper.
Why use px vs %?
Pixels are exact: 40px corners are 40px corners regardless of image size. Percentage is relative: 25% corners are 25% of the shorter side, so the same percentage produces visually-similar corners on different image sizes — useful when you are rounding several images for a consistent look.
Does it work with transparent PNGs?
Yes. The transparency of the input is preserved in non-rounded areas; the rounded corners become additionally transparent (or filled with your chosen background color).
What format is the output?
PNG — lossless and supports the alpha channel needed for transparent rounded corners. JPEG would not preserve transparency, so we always export PNG. Compress afterwards with our Compress Image if you need a smaller file.
What is the maximum corner radius?
Half of the shorter side of the image. Anything past that doesn't make geometric sense — the corners would overlap. Setting radius to exactly half (or using Full circle) produces a perfect circle.
Is there a file size limit?
Only your browser's memory. ToolChop handles 4K+ images without issue. The corner-rounding itself is a single Canvas clip operation — it scales with image size but stays fast.
Why use ToolChop instead of an online rounder that uploads my image?
Privacy and speed. Avatars and brand assets are often private until launch, and uploading them to a third party to apply a 30-pixel radius is exactly the unnecessary data path you should avoid. ToolChop runs entirely in your browser — verify in DevTools → Network that no request fires.