tldraw is a free, open-source infinite-canvas whiteboard: shapes, arrows, sticky notes, freehand drawing, real-time multiplayer collaboration with live cursors, and an AI feature that converts hand-drawn UI sketches into working HTML/CSS. Also ships as an embeddable React SDK for developers.
Free web app for individual/casual use, no login required. Developer SDK: 100-day free trial, then a startup license around $6,000/year (teams up to 10); commercial tiers scale up to ~$500/month.
Designers and teams wanting a fast, no-signup collaborative whiteboard for free, and developers wanting to embed a canvas editor into their own product via the SDK.
The AI sketch-to-code feature (hand-drawn UI to working HTML/CSS) is worth trying specifically for quick wireframe-to-prototype workflows, distinct from tldraw's core whiteboarding use.
