Stack Sketch vs Eraser
Eraser (eraser.io) is the most direct comparison on this list: both tools exist for technical diagrams, both have AI generation, both target engineers. The philosophical split is the input: Eraser leans diagram-as-code — write their DSL, get a diagram — while Stack Sketch is canvas-first: drag real icons, and let AI fill in the structure when words are faster.
| Stack Sketch | Eraser | |
|---|---|---|
| Primary input | Canvas-first (+ AI prompts) | Code-first (their DSL) |
| AI diagram generation | Yes — in your browser, your API key | Yes — hosted (their servers) |
| Prompts stay on your machine | Yes (no server endpoint at all) | No — processed by their service |
| MCP server for AI editors | Yes (npx @stack-sketch/mcp) | Not offered |
| Docs + diagrams in one workspace | No — diagrams only | Yes |
| Live share links | Yes — read-only, always current | Yes |
| Pricing | Free (10 diagrams) · $4.99/mo · $49.99 lifetime | Free tier; per-user paid plans |
Where Eraser wins
- Diagram-as-code: diagrams defined in text, reviewable in PRs.
- Docs and diagrams live together in one workspace.
- Team workspaces with collaborative editing.
- DiagramGPT made AI diagram generation mainstream.
Where Stack Sketch wins
The privacy architecture is the deepest difference. Eraser's AI runs through their service; Stack Sketch has no AI endpoint at all — your prompt goes from your browser to your model provider with your own key. For diagrams that describe internal infrastructure, that's not a nicety, it's the whole question.
Stack Sketch also ships an MCP server, so AI editors like Claude Code and Cursor can create and edit diagrams directly — the diagram-as-code workflow, but the code is your agent's tool calls. And the pricing is individual-friendly: a free tier with AI included, five dollars a month, or a one-time lifetime purchase — no per-user math.
The honest verdict
Choose Eraser if your team lives in text and wants diagrams versioned as code beside docs. Choose Stack Sketch if you want a visual canvas with real icons, AI that never sees your prompts server-side, and a lifetime price.