Anatomy vs Excalidraw
Which should you use? A side-by-side look at what each one does, who it suits, what it costs, how hard it is to set up, and where each falls short.
Open source · MIT
A Claude skill that builds interactive isometric SVG illustrations of machines to explain technical ideas.
Open source · MIT
Open-source virtual whiteboard for sketching hand-drawn style diagrams in your browser.
The short answer
Choose Anatomy if you need…
- Developers who want an explanatory diagram of a system or algorithm they can interact with
- Students learning how a mechanism or technical concept works
- Teachers preparing interactive visual explanations
- People already using Claude Code, Codex, OpenCode, or Antigravity who want illustrations from their agent
Choose Excalidraw if you need…
- Teams sketching diagrams or wireframes together in a shared canvas
- People who want a casual, informal look for explanatory drawings
- Developers who want to embed a whiteboard editor in their own React app
- Users who care about end-to-end encryption for shared drawings
Side-by-side
| Anatomy | Excalidraw | |
|---|---|---|
| Type | AI model / agent | App |
| Price | Free and open source | Free and open source |
| Licence | MIT | MIT |
| GitHub stars | 24k | 135k |
| Setup difficulty | Beginner | Beginner |
| How you get it | Install with a package manager | Use it in the browser (or self-host) |
| Main language | JavaScript | TypeScript |
| Last code update | 18 days ago | 4 days ago |
What each one is
Anatomy
Anatomy is an agent skill for Claude and other coding agents. You ask for a figure explaining a technical idea, and it builds a physical object whose working mirrors that idea, drawn as an interactive isometric SVG with optional WebGL shader effects and beta 3D parts. The README says it uses only Node's built-in modules and needs no API keys.
Excalidraw
Excalidraw is an open-source whiteboard where you draw diagrams, wireframes and sketches in a deliberately hand-drawn style. The hosted app at excalidraw.com adds real-time collaboration, end-to-end encryption and autosave to the browser. The same editor is also published as an npm package that developers can embed in their own apps.
Best for
Anatomy
- Developers who want an explanatory diagram of a system or algorithm they can interact with
- Students learning how a mechanism or technical concept works
- Teachers preparing interactive visual explanations
- People already using Claude Code, Codex, OpenCode, or Antigravity who want illustrations from their agent
Excalidraw
- Teams sketching diagrams or wireframes together in a shared canvas
- People who want a casual, informal look for explanatory drawings
- Developers who want to embed a whiteboard editor in their own React app
- Users who care about end-to-end encryption for shared drawings
- Anyone who wants drawings saved in an open .excalidraw JSON format
Strengths
Anatomy
- Installs with one command and needs no API keys or extra npm packages, per the README
- Figures are built to be interactive and to show live readouts from the same model that moves the parts
- Works across several agents (Claude Code, Antigravity, OpenCode, Codex, MiniMax Code) under the MIT license
Excalidraw
- Free and open source under the MIT license
- Simple, approachable drawing tools with a distinctive hand-drawn look
- Open .excalidraw JSON format and export to PNG, SVG and clipboard
Not ideal for
Anatomy
- Users who need plain static diagrams or charts for data reports, since the output is stylized isometric art
- People without a supported coding agent, because the skill runs inside one
- Anyone needing production-ready 3D graphics; the README labels the 3D mode as beta
Excalidraw
- Users who need precise, pixel-perfect vector design; the hand-drawn style is the default look and the README does not describe precision tools
- People wanting to self-host the collaboration service; the README only links to the hosted app for real-time collaboration and does not describe a self-hosting setup
- Non-developers who only want the hosted app and have no need for the code; the npm and development sections are aimed at developers
Trade-offs
Anatomy
- The 3D mode is marked beta and is limited to a few moving parts in the examples
- Output depends on the underlying agent's model, so results will vary with the prompt and agent used
- The README is truncated, so details of the full feature set and limits are not fully visible here
Excalidraw
- Collaboration and encryption are features of the hosted app; the README does not detail how to run them yourself
- Development setup is covered only by a linked guide, so the README alone gives limited build detail
- No downloadable binaries in the latest release; use the web app or the npm package
Getting started
Anatomy
Install for Claude Code (global)
npx skills add wheresryan22/anatomy -g -a claude-codeInstall with the skills CLI, prompting for agents
npx skills add wheresryan22/anatomy -gFrequently asked questions
What is the difference between Anatomy and Excalidraw?
Anatomy: A Claude skill that builds interactive isometric SVG illustrations of machines to explain technical ideas. Excalidraw: Open-source virtual whiteboard for sketching hand-drawn style diagrams in your browser. Anatomy suits developers who want an explanatory diagram of a system or algorithm they can interact with, while Excalidraw suits teams sketching diagrams or wireframes together in a shared canvas.
Are Anatomy and Excalidraw free?
Anatomy: Free and open source. Excalidraw: Free and open source.
Is Anatomy or Excalidraw more popular?
Excalidraw has more GitHub stars (135k) than Anatomy (24k). Popularity isn't the same as fit — check which one matches your use case above.
What are other alternatives to Anatomy and Excalidraw?
Other options people compare them with include Mermaid, watermarks-remover, Drawnix.
Keep comparing
Built from our catalogue entries for both products: open-source details come from each project's README (AI-assisted, refreshed weekly) and GitHub data; AI-tool details are editorial. Spotted something wrong? Let us know from either product's page.