Flameshot

Flameshot is a free, open‑source screenshot utility available on Windows, macOS and Linux. It lets you capture the entire screen, a window, or a custom region, then instantly annotate with arrows, boxes, text, blur, and pixelate. Built‑in editing tools let you highlight, crop and copy to clipboard or save directly. Highly customizable shortcuts and a simple UI make quick captures effortless for developers, designers and anyone needing fast visual feedback.