Excalidraw

Optimize for getting ideas onto a canvas before polishing the diagram

The README lists an infinite canvas, hand-drawn styling, rectangles, circles, arrows, free-draw tools, images, shape libraries, undo/redo, zoom and panning, PNG/SVG/clipboard export, and an open .excalidraw JSON format. That combination makes it especially useful for rough architecture sketches, wireframes, and explanatory diagrams where speed matters more than pixel-perfect layout.

Sources: [1]

Use it as a standalone whiteboard or embed the editor into a React product

The official README publishes @excalidraw/excalidraw as an npm package and documents installing it together with React and React DOM. The repository itself is a TypeScript-based monorepo using React type definitions, Vite, Vitest, and related frontend tooling. This gives teams an integration path when a drawing canvas needs to become part of a larger product rather than remain a separate web app.

Sources: [1][2]

The official web app adds offline use, collaboration, E2E encryption, and local-first storage

The README states that excalidraw.com supports PWA/offline operation, real-time collaboration, end-to-end encryption, local-first browser autosave, and shareable read-only links. That lets the same editor span personal sketching and live collaborative whiteboarding.

Sources: [1]

A strong fit for architecture sketches, wireframes, meeting notes, and lightweight visual collaboration

It is a practical choice when teams need to visualize system structure, UI ideas, concepts, or discussion flow quickly without the overhead of a formal diagramming or design tool. Developers can use it for design discussions and documentation, product teams for wireframes and brainstorming, and application teams can evaluate the npm package when they need an embedded whiteboard.

Do not assume the npm package exposes every feature available on excalidraw.com

The README separates the editor package from the features of the hosted excalidraw.com application. Real-time collaboration, end-to-end encryption, local-first behavior, and shareable links are described as app features, with drop-in plugins mentioned as future work. For embedded use, verify the library APIs you actually need instead of assuming parity with the hosted app.

The source code is MIT licensed, while commercial services such as Excalidraw+ exist around the project. Evaluate reusable OSS code separately from features or operations that belong to the hosted commercial offering.

Sources: [1][3]