Excalidraw

Excalidraw is an open source virtual whiteboard for drawing hand-drawn style diagrams, wireframes, and sketches. It provides an infinite canvas with common diagramming tools, so teams and individuals can turn ideas into visual drawings in a browser.

The editor includes rectangles, circles, diamonds, arrows, lines, free-draw, and an eraser, plus arrow binding, labeled arrows, undo and redo, zoom, and panning. It supports images, shape libraries, dark mode, PNG and SVG export, clipboard export, and an open .excalidraw JSON file format.

The hosted Excalidraw app is a PWA that works offline, autosaves to the browser, supports real-time collaboration, and uses end-to-end encryption for collaboration. Excalidraw is also available as an npm package for embedding the editor in other apps.