Can I open-source Mermaid Chart?
KINDA · partial or early alternativesKinda. draw.io and Excalidraw cover the core of Mermaid Chart, but they're early or partial — expect gaps like high-fidelity import and export and presentation and enterprise controls.
Mermaid Chart: The shapes are easy; customers pay for low-friction editing, reliable exports, collaboration, and a canvas that never fights them.
xhigh-fidelity import and export
xpresentation and enterprise controls
xmultiplayer cursors and comments
xlarge template libraries
These projects already replace it, free.
EExcalidrawVirtual hand-drawn style whiteboard for sketching diagrams collaborativelyopen source↗Ddraw.ioThe diagramming workhorse — flowcharts, architecture diagrams, UML — runs fully client-side or as your own container.open source↗What each one is, in full: Excalidraw · draw.io
no votes, no pay-to-list · just what's real
Mermaid Chart pricing
| plan | monthly | annual (per mo) | what you get |
|---|---|---|---|
| basic | $0/user | $0/user | Up to 3 diagrams; 1 team and 1 project; limited AI usage (credit cap not publicly quantified) |
| plus | — | $10/user | Unlimited diagrams and diagram size; 300 AI credits/year; view-and-comment collaboration |
| premium | — | $20/user | Unlimited diagrams; 2,000 AI credits/year; unlimited viewer seats, teams and projects; co-editing and SSO |
| enterprise | custom | — | Premium features; custom contracts, support and enterprise controls; numeric caps custom |
free tierUp to 3 hosted diagrams; 1 team and 1 project; limited AI usage (no numeric AI-credit cap published)
billingpaid self-serve plans are annual only; no month-to-month plan
hidden costsPaid prices are per user. Included AI credits reset on the plan cadence; Enterprise pricing and any extra-credit pricing are not published.
verified 2026-08-12 · source ↗
Can I open-source Mermaid Chart?
Kinda. Excalidraw covers the core of Mermaid Chart, but there are real gaps: high-fidelity import and export, presentation and enterprise controls. Read the honest list above before committing.
How much does Mermaid Chart cost?
Mermaid Chart's pricing is usage-based or varies by plan · The official pricing URL is recorded, but a stable current amount was not safely recoverable in this pass. Do not publish a number until rechecked..
What do I lose by replacing Mermaid Chart?
Honestly: high-fidelity import and export; presentation and enterprise controls; multiplayer cursors and comments; large template libraries. If any of those are load-bearing for you, keep paying.
Is there an open-source alternative to Mermaid Chart?
Yes: Excalidraw (Virtual hand-drawn style whiteboard for sketching diagrams collaboratively) draw.io (The diagramming workhorse — flowcharts, architecture diagrams, UML — runs fully client-side or as your own container.)