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
You pay

$6/mo

$72/yr

Per seat. Read off the official pricing page.

You’d pay instead

$50one-off30 h to build

$50/mo6 h/mo upkeep

On cash alone, building overtakes the subscription at 10 seats.

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. All Excalidraw+ alternatives, with the arithmetic →

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 trustTrusted by the largest companies in the world
Read the build prompt

First-year cost

Keep paying

Paying is—cheaper in year one.

On cash alone, building overtakes the subscription at 10 seats.

Paid seatsseats

Money you would actually spend

Keep paying
—

Subscription price × seats × 12

Build it
—

AI build —APIs + hosting —

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

Not run yet
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 checked5 sources · 2/3 runs agreed · evidence score 89

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.

Integrity checks

What held up, and what did not.

✓ Price read off the page! 2 of 3 runs agreed; the verdict is the majority✓ Citations limited to fetched pages! 1 moat quoted from the page