Stack Sketch vs draw.io
draw.io (diagrams.net) is the default answer to "free diagramming tool" — open source, offline-capable, and mature enough to have shape libraries for nearly everything. Stack Sketch is a much narrower tool: it only does software-architecture and infrastructure diagrams, and it optimizes everything for that one job.
| Stack Sketch | draw.io | |
|---|---|---|
| Real technology icons | 640+ built in, ⌘K search | Generic shape libraries |
| AI diagram generation | Yes — in your browser, your API key | None |
| Live share links | Yes — read-only, always current | File exports / storage integrations |
| MCP server for AI editors | Yes (npx @stack-sketch/mcp) | Not offered |
| Offline & desktop apps | No — browser only | Yes |
| Open source | No — closed-source commercial | Yes |
| UML / BPMN / ERD | No — architecture diagrams only | Yes |
| Pricing | Free (10 diagrams) · $4.99/mo · $49.99 lifetime | Free |
Where draw.io wins
- Completely free and open source, with no account required.
- Works offline, with desktop apps and self-hostable editors.
- Deep general-purpose shape libraries: UML, BPMN, ERD, network topologies, floorplans.
- Integrations with Confluence, Google Drive and other storage backends.
Where Stack Sketch wins
draw.io gives you a blank canvas and generic shapes; an architecture diagram is something you assemble by hand. Stack Sketch starts from 640+ real, brand-colored technology icons (press ⌘K and type "postgres"), so a stack diagram reads like the stack it describes — and takes minutes, not an afternoon.
There is no AI in draw.io. In Stack Sketch you can describe a system in a sentence and get a full draft on the canvas, using your own API key with generation running in your browser. And when the diagram is done, you publish a live read-only link instead of exporting a file that starts rotting immediately.
The honest verdict
Choose draw.io if you need offline editing, UML/BPMN, or a fully open-source tool. Choose Stack Sketch if you're drawing tech-stack and infrastructure diagrams and want them fast, current and presentable.