Mermaid

Mermaid (mermaid.ai, formerly Mermaid Chart) is the commercial diagramming app built by the team behind Mermaid.js, the open-source library that turns plain-text definitions into diagrams and that GitHub, documentation tools and AI chat assistants render natively. The app adds an editor, AI, collaboration and integrations on top of that text format. The company moved the product from mermaidchart.com to mermaid.ai in December 2025.

How it works

You can prompt inside the canvas or the code panel, upload a document or paste a transcript, or write Mermaid syntax directly; each diagram stays editable both as code and on a visual canvas with shapes, colours and themes. Mermaid AI suggests the diagram type that fits the input: flowchart, sequence diagram, Gantt chart, ER diagram, timeline, mind map, org chart, class, state or user-journey diagram, and more. Because the source is text, diagrams diff cleanly and live well in repositories and docs.

Integrations

• An MCP server so Claude, VS Code, Cursor and other clients can generate diagrams straight into Mermaid.
• Plugins for IDEs and for documentation and wiki tools, plus presentations built from diagrams.
• Mermaid Flow (public beta since September 2026, at flow.mermaid.ai): lay out an AI workflow as a diagram, connect services and run it, with every step and run recorded on the canvas.

Pricing

Billed annually. Basic is free with up to 6 diagrams, limited diagram size and 15 AI credits. Plus is $10 per user per month with unlimited diagrams and 300 AI credits a year. Premium is $20 per user per month with 2,000 AI credits a year and unlimited free viewer seats. Enterprise adds SSO, custom contracts and a dedicated customer success manager. The company cites SOC 2 compliance.

Who it is for

Software, infrastructure and data engineers, technical writers and consultants who already think in diagrams-as-code and want AI to draft them and teammates to edit them.