Mermaid Diagram Editor
Free online Mermaid diagram editor. Write flowchart, sequence, class, ER, Gantt, pie, and mindmap diagrams with live preview, 6 themes (default, base, dark, forest, neutral, neo), SVG/PNG export, and local history. Rendering runs 100% in your browser.
How to use
- Type or paste Mermaid code (flowchart, sequence, class, state, ER, Gantt, pie, mindmap); try a sample.
- Pick one of 6 themes.
- Export SVG/PNG; press Save to history to keep up to 30 snapshots locally.
FAQ
Is my diagram uploaded?
No. Mermaid renders locally via the mermaid library in your browser. Nothing leaves your device.
Which diagram types work?
Flowchart, sequence, class, state, ER, Gantt, pie, and mindmap — anything the bundled Mermaid version supports.
Where is history stored?
In this browser's localStorage, up to 30 snapshots. Press Save to history, then Load any entry later.