Excalidraw

Excalidraw is a free, open-source virtual whiteboard for sketching diagrams, flowcharts, wireframes and illustrations in a deliberately hand-drawn style. The editor at excalidraw.com needs no account: you open it and start drawing on an infinite canvas, share a link for real-time collaboration, and export to PNG, SVG or a file. The code is MIT-licensed and also ships as the @excalidraw/excalidraw React component that other products embed.

AI features

• Text to diagram: describe a flow, a process or a system in plain language and get an editable diagram on the canvas, built from ordinary Excalidraw shapes you can keep moving and restyling.
• Mermaid to Excalidraw: paste Mermaid code and convert it to native shapes. This path uses no AI, has no request limit and gives the same output every time.
• Wireframe to code: sketch screens on the canvas and generate interactive mockups from them.
• MCP and REST API (public beta, Excalidraw+): point Claude, Codex, Cursor or another MCP client at a workspace and let the agent draw into it, for example an architecture diagram from a repository or wireframes from a spec. Keys are scoped read-only or write, and every API call is logged.

Pricing

• Free: the full editor, one infinite scene, unlimited collaborators, end-to-end encryption in the browser and 10 AI requests a day.
• Excalidraw+ ($6 per user per month, 14-day trial): unlimited cloud-saved scenes and folders, team workspaces, comments, presentations with PDF and PPTX export, voice hangouts, 100 AI requests a day, the MCP server and REST API, and bring-your-own-key for OpenAI, Anthropic, Gemini, Grok or OpenRouter with no Excalidraw limit. Excalidraw+ is SOC 2 Type 2 audited.

Who it is for

Engineers, product managers and designers who want a quick, low-fidelity way to explain a system or rough out a screen, and teams who want agents to produce diagrams they can still edit by hand. The sketchy look is the point: it keeps a diagram feeling like a draft, which invites feedback rather than polish.