Open-source Cacoo alternatives

Excalidraw is a browser-based whiteboard that renders shapes, arrows and text in a deliberately hand-drawn style, which makes diagrams feel like quick sketches rather than polished slides. It is used for architecture diagrams, wireframes, brainstorming and teaching, and works on an infinite canvas with zoom and pan.

The editor offers rectangles, circles, diamonds, arrows, lines, free-draw and an eraser, along with labeled arrows that stay bound to shapes, image support, shape libraries, dark mode and undo and redo. Drawings export to PNG, SVG or the clipboard, or to an open JSON-based .excalidraw file. The hosted app adds real-time collaboration with end-to-end encryption, offline use as a progressive web app, autosave in the browser and shareable read-only links.

The editor is also published as an npm package under the MIT license, so developers can embed it in their own products and customize it. A separate paid plan, Excalidraw+, is linked from the project for people who want a hosted workspace.

tldraw is an SDK for building infinite canvas applications in React. It supplies a complete canvas engine that serves as the foundation for whiteboards, diagramming tools, design editors and other canvas products, and it ships a default whiteboarding tool set that you can use as is or replace with your own primitives.

Out of the box it offers pressure-sensitive drawing, geometric shapes, rich text, arrows with snapping, image and video support and image export. Developers can extend it with their own shapes, tools, bindings, interface components, side effects and event hooks, and can drive the canvas at runtime through the Editor API. Multiplayer collaboration is available through a self-hostable sync package, there are canvas primitives for building with LLMs, and the DOM-based rendering can embed websites such as YouTube, Figma and GitHub. It works in desktop and touch browsers.

Starter kits provide the custom shapes, tools and interface for common application types, and each kit is MIT licensed. The SDK itself is under tldraw's own license rather than a standard open-source one, so review the terms before shipping it in a commercial product.

Drawnix is a free, open-source whiteboard that brings mind maps, flowcharts and freehand drawing together in a single workspace. Instead of switching between separate diagramming apps, you can sketch ideas, structure them into diagrams and annotate everything on one infinite canvas that you can zoom and scroll freely.

The editor supports inserting images, undo and redo, copy and paste, light and dark themes, and a layout that adapts to mobile devices. Mermaid syntax can be converted into flowcharts and Markdown text into mind maps, while work is saved automatically in the browser and can be exported as PNG images or as .drawnix JSON files for later reuse.

Drawnix is released under the MIT licence and is built on Plait, an open-source drawing framework from the PingCode team, using a plugin architecture that can work with different UI frameworks. The hosted app at drawnix.com is a minimal version, and the repository includes Docker instructions for people who prefer to run their own copy.

draw.io is a diagramming and whiteboarding application, with many configuration options, written in JavaScript and running entirely in the browser. It is co-owned and built by draw.io Ltd (formerly JGraph) and draw.io AG, and the same code powers the production deployment at app.diagrams.net.

The repository's source code uses the Apache License 2.0, while the icon sets, stencil libraries and diagram templates come with extra terms, including a restriction on using them in Atlassian products or marketplace plugins without written permission, although diagrams you create are unaffected and the project makes no copyright claim on them. The scope is diagramming and whiteboarding, not SVG editing, and this version does not offer real-time collaborative editing.

The team does not accept pull requests; development is done entirely by the core team. Because the editor is client-side, it can be embedded or hosted on your own infrastructure, and the hosted app is free to use in a browser. It suits anyone drawing flowcharts, architecture diagrams, network maps or UML.