The best open source alternative to Excalidraw is Tldraw. If that doesn't suit you, we've compiled a ranked list of other open source Excalidraw alternatives to help you find a suitable replacement. Other interesting open source alternative to Excalidraw is Penpot.
Excalidraw alternatives are mainly Online Design Tools but may also be Collaborative Workspaces or Whiteboarding Tools. Browse these if you want a narrower list of alternatives or looking for a specific functionality of Excalidraw.
Virtual whiteboard that works instantly on any device, no signup required, with real-time multiplayer collaboration built in.

tldraw is a free virtual whiteboard that opens in your browser and works immediately. No account, no installation, no waiting. It runs on desktop, tablet, and mobile, making it practical for quick sketches, brainstorming sessions, or visual collaboration across teams.
The core experience is fast and low-friction. You get a clean infinite canvas with drawing tools, shapes, text, arrows, and sticky notes. Real-time multiplayer is built in, so multiple people can draw and edit together without any setup. Share a link and collaborators are in.
What sets tldraw apart from tools like Excalidraw or draw.io is its focus on feel. The drawing experience is deliberately smooth, with snapping, alignment guides, and a hand-drawn aesthetic that makes diagrams feel approachable rather than stiff. It's well-suited for informal collaboration: wireframes, quick diagrams, meeting notes with visuals, or just thinking out loud with a colleague.
Key capabilities include:
tldraw is also available as an open-source SDK, which means developers can embed the whiteboard engine directly into their own products. That dual nature (polished end-user tool and embeddable component) gives it a broader reach than most LucidChart alternatives in this space.
Looking for open source alternatives to other popular services? Check out other posts in the alternatives series and openalternative.co, a directory of open source software with filters for tags and alternatives for easy browsing and discovery.
Design, prototype, and hand off to developers in one platform. Supports design systems, tokens, flexible layouts, and AI workflows with real CSS/HTML output.

Penpot is a browser-based design and prototyping platform built for teams working on digital products. It covers the full design process, from early wireframes through polished UI, interactive prototypes, and developer handoff, without requiring separate tools for each stage. It's self-hostable, so teams with strict data requirements can run it on their own infrastructure.
The core workflow connects designers and developers more directly than most tools. Instead of exporting assets and writing specs separately, Penpot generates 1:1 CSS, HTML, SVG, and JSON directly from the design. What you see in the canvas is what developers get in code, which cuts down on the back-and-forth that usually happens during implementation.
Key capabilities include:
Penpot is a practical alternative to Sketch or Adobe XD for teams that want full control over their tooling. Because it's open source and web-native, there's no per-seat licensing tied to a vendor's pricing decisions, and it works across operating systems without a desktop install.
It suits product teams where designers and engineers work closely together, particularly those building design systems at scale or looking to bring AI tooling into their existing design process.