A circle crop cuts a square area of a photo into a round shape and makes everything outside the circle transparent. The result is a PNG you can place on any background, which is what websites, email signatures, team pages and slide decks need for round headshots.
Open a photo, then drag it under the round frame and use the zoom slider (or pinch on a phone) to choose what sits inside the circle. The arrow keys nudge the photo when the frame has focus. You can add a border ring in any colour and thickness, and choose the output size: the circle's own pixel size, or a fixed 256, 512 or 1024 px for avatars. A live preview shows the finished round image on a checkerboard so you can see the transparent corners.
The output is always PNG, because JPG can't store transparency. Edges are anti-aliased so the circle looks smooth rather than jagged. One photo is cropped per run. Social networks such as WhatsApp, LinkedIn and Instagram crop profile photos into circles themselves, so for those a square 1:1 image also works; a transparent round PNG is useful where you place the image yourself.