Mermaid Live Editor — Diagram Generator
Free online Mermaid diagram editor. Create flowcharts, sequence diagrams, class diagrams, Gantt charts, pie charts, and mind maps. Export to SVG or PNG. No sign-up required.
Preview will appear here...
What Is Mermaid?
Mermaid is a JavaScript-based diagramming and charting tool that renders Markdown-inspired text definitions to create and modify diagrams dynamically. It supports flowcharts, sequence diagrams, class diagrams, state diagrams, Gantt charts, pie charts, ER diagrams, and mind maps. Mermaid is widely used in documentation, README files, and technical wikis.
How to Use This Mermaid Editor
- Type or paste Mermaid syntax in the editor panel on the left.
- The diagram preview updates automatically as you type.
- Choose a theme (default, dark, forest, neutral) to change the diagram style.
- Click sample buttons to load example diagrams for different chart types.
- Export your diagram as SVG (vector) or PNG (raster) using the export buttons.
Common Use Cases
- Create Architecture Diagrams — Quickly sketch system architecture, data flow, or deployment diagrams using simple text syntax.
- Generate Sequence Diagrams — Document API interactions, authentication flows, or microservice communication patterns.
- Project Planning with Gantt Charts — Visualize project timelines, task dependencies, and milestones.