Excalidraw is a free, open-source virtual whiteboard application designed for creating hand-drawn-style diagrams, wireframes, and sketches with a collaborative, browser-based experience. It solves the problem of overengineered diagramming tools by offering a simple, intuitive interface that produces visually appealing sketches with a distinctive informal, hand-drawn aesthetic. Excalidraw requires no sign-up and works instantly in the browser, making it the fastest way to create diagrams for documentation, architecture discussions, and brainstorming sessions.
Excalidraw provides a curated set of drawing primitives including rectangles, ellipses, diamonds, arrows, lines, and freehand drawing, all rendered with a hand-drawn look that makes diagrams feel approachable and informal. It supports real-time end-to-end encrypted collaboration, a community library of reusable components and icons, dark mode, export to PNG, SVG, and clipboard, and local-first storage that keeps data on the user device. The Excalidraw ecosystem includes an NPM package for embedding into React applications and VS Code extensions for diagramming within the editor.
Excalidraw is beloved by software engineers, technical writers, architects, and educators who need to quickly create system architecture diagrams, sequence flows, database schemas, and explanatory visuals. Its hand-drawn style is particularly valued in technical documentation and blog posts where formal diagrams feel too rigid. Excalidraw integrates with Notion, Obsidian, Logseq, and other knowledge management tools through plugins, and its open-source React component can be embedded into any web application for custom diagramming needs.