diagram-design 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
An agent skill that draws editorial diagrams as one self-contained HTML + SVG file.
Open source · MIT
Open-source virtual whiteboard for sketching hand-drawn style diagrams in your browser.
Our verdict
diagram-design is an agent skill: you describe a diagram in plain words to a coding agent like Claude Code or Cursor, and it outputs one HTML/SVG file you can open in any browser. Excalidraw is a hand-drawn-style whiteboard you draw on yourself in the browser, with real-time collaboration on its hosted app. They solve different problems, so pick based on whether you want an AI to generate the diagram or a shared canvas to sketch on.
Pick diagram-design if you already use a supported AI coding agent and want clean architecture or flow diagrams generated from a description, matched to your brand.
Pick Excalidraw if you want to sketch or draw diagrams yourself, often with teammates on a shared canvas, in an informal hand-drawn style.
| Key difference | diagram-design | Excalidraw |
|---|---|---|
| What it is | Agent skill that generates a single HTML/SVG diagram file | Browser whiteboard app you draw on, also an embeddable npm package |
| Who makes the diagram | The AI agent chooses the type and writes the file | You draw it yourself with simple tools |
| Collaboration | README does not mention live or collaborative editing | Real-time collaboration on the hosted app at excalidraw.com |
| Setup | Needs a supported coding agent; installed as a skill | Open in the browser; no install needed for the hosted app |
| Price and licence | Free and open source under MIT | Free and open source under MIT |
Written with AI from both products' catalogue entries · updated 2026-10-29
Who each one is for
Choose diagram-design if you need…
- Developers who already use a supported coding agent and want architecture or flow diagrams without learning a diagram language
- Teams that want diagrams to follow their own brand colors and fonts
- People who want diagrams they can open by double-clicking, with no server needed
- Anyone who wants to import existing Mermaid, draw.io, or Excalidraw files and redraw them
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
| diagram-design | Excalidraw | |
|---|---|---|
| Type | AI model / agent | App |
| Price | Free and open source | Free and open source |
| Licence | MIT | MIT |
| GitHub stars | 64.2k | 135k |
| Setup difficulty | Beginner | Beginner |
| How you get it | Install with a package manager | Use it in the browser (or self-host) |
| Main language | HTML | TypeScript |
| Last code update | 5 days ago | 4 days ago |
What each one is
diagram-design
Diagram Design is a skill you add to a coding agent such as Claude Code, Codex, Cursor, or GitHub Copilot. You describe the diagram you want in plain words, and the agent produces a single HTML file containing SVG that you can open in a browser. The README says it supports 45 diagram types and can match your site's palette and fonts after you run an onboarding step.
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
diagram-design
- Developers who already use a supported coding agent and want architecture or flow diagrams without learning a diagram language
- Teams that want diagrams to follow their own brand colors and fonts
- People who want diagrams they can open by double-clicking, with no server needed
- Anyone who wants to import existing Mermaid, draw.io, or Excalidraw files and redraw them
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
diagram-design
- Output is one self-contained HTML and SVG file that opens without extra tooling
- Works across many agent hosts, with installation steps documented for each
- Licensed under MIT
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
diagram-design
- People without a supported AI coding agent, since the project is delivered as an agent skill and the README does not describe a standalone app
- Anyone who needs live, collaborative diagram editing, which the README does not mention
- Teams that need a fully manual drag-and-drop editor, because the agent chooses the diagram type and writes the file
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
diagram-design
- The README does not state a release version, so update behavior depends on each host's install path
- Quality and type choice depend on the agent that runs the skill, which the README does not evaluate
- Some install paths (such as the Cowork organization marketplace) require extra setup like mirroring the repository
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
diagram-design
Install the skill with the cross-agent skills CLI
npx skills add cathrynlavery/diagram-designAdd the Claude Code plugin marketplace
/plugin marketplace add cathrynlavery/diagram-designFrequently asked questions
Should I use diagram-design or Excalidraw?
diagram-design is an agent skill: you describe a diagram in plain words to a coding agent like Claude Code or Cursor, and it outputs one HTML/SVG file you can open in any browser. Excalidraw is a hand-drawn-style whiteboard you draw on yourself in the browser, with real-time collaboration on its hosted app. They solve different problems, so pick based on whether you want an AI to generate the diagram or a shared canvas to sketch on. Pick diagram-design if you already use a supported AI coding agent and want clean architecture or flow diagrams generated from a description, matched to your brand. Pick Excalidraw if you want to sketch or draw diagrams yourself, often with teammates on a shared canvas, in an informal hand-drawn style.
What is the difference between diagram-design and Excalidraw?
diagram-design: An agent skill that draws editorial diagrams as one self-contained HTML + SVG file. Excalidraw: Open-source virtual whiteboard for sketching hand-drawn style diagrams in your browser. diagram-design suits developers who already use a supported coding agent and want architecture or flow diagrams without learning a diagram language, while Excalidraw suits teams sketching diagrams or wireframes together in a shared canvas.
Are diagram-design and Excalidraw free?
diagram-design: Free and open source. Excalidraw: Free and open source.
Is diagram-design or Excalidraw more popular?
Excalidraw has more GitHub stars (135k) than diagram-design (64.2k). Popularity isn't the same as fit — check which one matches your use case above.
What are other alternatives to diagram-design and Excalidraw?
Other options people compare them with include Mermaid, drawio-skill, fireworks-tech-graph, Kami, Taste Skill.
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.