Question 1

What is Mermaid and what diagrams can it create?

Accepted Answer

Mermaid is a JavaScript-based diagramming tool that renders text definitions into diagrams and charts. It supports flowcharts, sequence diagrams, class diagrams, state diagrams, entity-relationship diagrams, Gantt charts, pie charts, git graphs, and more. Diagrams are defined in a simple markdown-like syntax, making them easy to write, version-control, and embed in documentation.

Question 2

How do I write a flowchart in Mermaid?

Accepted Answer

Start with 'flowchart TD' (top-down) or 'flowchart LR' (left-right). Define nodes with labels in brackets: A[Start]. Connect nodes with arrows: A --> B. Use curly braces for decision diamonds and double parentheses for circles. Conditional branches use labels on arrows: B -- Yes --> C. You can also style nodes with classDef and apply classes with :::className.

Question 3

Can I export Mermaid diagrams as images?

Accepted Answer

Yes — this editor lets you export any rendered diagram as an SVG file, which scales perfectly at any resolution. SVG files can be opened in browsers, Figma, Inkscape, and most vector editors. For PNG or PDF export, you can open the SVG in a browser and print to PDF, or use tools like Puppeteer, mermaid-js CLI, or the official Mermaid Live Editor at mermaid.live.

Question 4

How do I use Mermaid in Markdown documentation?

Accepted Answer

GitHub, GitLab, Notion, Obsidian, and many other platforms natively render Mermaid diagrams in Markdown files. Wrap your diagram code in a fenced code block with the mermaid language tag. For platforms without native support, you can use the mermaid.js library or embed the rendered SVG directly in your HTML.

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Mermaid 图表编辑器

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