Excalidraw
Virtual collaborative whiteboard.
Virtual whiteboard for sketching hand-drawn style diagrams, system designs, and wireframes.
About Excalidraw
Excalidraw is an open-source, minimal virtual whiteboard tool with a hand-drawn aesthetic. It's loved by developers for quickly sketching architecture diagrams, system designs, wireframes, flowcharts, and ERDs without the complexity of full diagramming tools.
Everything on Excalidraw has a slightly imperfect, sketchy look that signals "this is a work in progress" — making it perfect for technical discussions where pixel-perfect design isn't the point. The tool runs entirely in the browser, requires no login, and files are stored locally or in the URL.
Real-time collaboration is built in — share a link and multiple people can draw together. Excalidraw has an extensive library of components (including AWS, GCP, and Azure icons) for drawing cloud architecture diagrams. Its VS Code extension lets you embed diagrams directly in your codebase.