Write Mermaid syntax, get a live SVG diagram. Flowchart, sequence, class, ER, Gantt, pie, state, journey — all client-side.
Type Mermaid code to render a diagram here.
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Mermaid is a text-based diagramming language used in GitHub READMEs, Notion docs, GitLab issues, and dozens of static-site generators. Write a few lines like "flowchart TD\n A --> B" and Mermaid renders a proper SVG diagram. The Mermaid Diagram Editor brings that workflow into your browser — paste or type Mermaid code on the left, get a live SVG on the right, then download as SVG (vector, perfect for documentation) or PNG (2x scale, ready for slides). Eight diagram types are supported: flowchart, sequence, class, state, ER, Gantt, pie, and journey. The Mermaid runtime (~500 KB) is loaded only when you open this page, never from the worker, and everything renders client-side so private architecture diagrams never leave your browser.
flowchart TD → top-down flowchart sequenceDiagram → request/response sequence classDiagram → UML class with inheritance stateDiagram-v2 → state machine erDiagram → entity-relationship (ER) gantt → project timeline pie → pie chart journey → user journey map