Design and diagrams decision
Excalidraw+
A single experienced developer can build a useful self-hosted/small-team replacement (canvas, save/load, exports, basic LLM diagramming) in about a week; Excalidraw+’s main durable advantage is brand trust rather than proprietary technical moat.
Visit website↗Open-source builds that already do this
Every project below is open source and already does this job today. Fork one, self-host it, or take the parts you need — the build prompt further down assumes an empty file, and this is the shortcut past that. Licences differ; check the one on each card before you ship.
What a replacement has to do
- Open a canvas, draw/modify shapes with pointer input, save/load scenes, export PNG/SVG, optionally generate a diagram from text via an LLM.
What it still won’t have
- enterprise features (teams management, access controls)
- cloud-hosted backups and server-side syncing at scale
- read-only embeds/managed sharing and workspace collections
- voice hangouts & screensharing integrated in product
- extended AI features and MCP integrations provided by vendor
What remains hard
- Brand trust
Trusted by the largest companies in the world
First-year cost
Keep paying
Paying is—cheaper in year one.
On cash alone, building overtakes the subscription at 10 seats.
Money you would actually spend
Time you would spend
—
What you would spend
What we assumed
The verdict above measures whether you could build it. This one is only about money.
Runnable build prompt
Build a minimal Excalidraw+ replacement using React for UI, HTML5 Canvas (or SVG) for drawing, Node.js + Express for an API, PostgreSQL (or S3) for scene storage, and a WebSocket server for realtime diffs. In scope: interactive canvas with shapes and freehand, save/load scenes to server, export PNG/SVG, user sign-in (email link or simple JWT), simple text-to-diagram integration using an LLM API (configurable key), and a small admin dashboard to view saved scenes. Out of scope: enterprise single-sign-on, paid billing, heavy multi-tenant scaling, advanced voice hangouts, and a hosted MCP. Require: input validation, conflict handling for concurrent edits, retry/backoff for external API calls, server-side rate limits, automated tests (unit for core logic, integration for API endpoints), and Dockerfiles for local dev and production. Provide README with deployment steps and health-check endpoints.
How we checked
How the score was reached
- Build verdict base78
- An open-source build was found+5
- 5 cited sources+3
- Price verified on pricing page+3
- Evidence score89
The base comes from the verdict. Everything under it is a check that either happened or did not, and each one is a fact frozen in this record rather than a judgement made at render time — so the same evidence always produces the same number.
How scoring works →Cited sources · 5
Every page the run actually retrieved.
- official productExcalidraw product page
- official pricingExcalidraw+ pricing
- official docsExcalidraw documentation
- open sourcelovasoa/whitebophir
- open sourcespacedeck/spacedeck-open
Integrity checks
What held up, and what did not.
