Mermaid Diagram Playground
Transform your architectural thoughts into professional diagrams instantly. Type Mermaid.js syntax and watch your flowchart, sequence diagram, or Gantt chart render in real-time.
100% Private & Secure
This tool runs completely inside your browser using client-side WebAssembly and JS. Zero data is ever sent to our servers.
How to use this tool
- Type or paste Mermaid.js syntax into the editor on the left
- Watch the live preview update instantly on the right
- Use the category buttons (Flow, Seq, Gantt) for quick templates
- Copy the generated SVG code for use in your documentation
Example Usage
Input
graph LR A --> B
Output
[SVG Diagram Rendering]
When to use this tool
- Visualizing system architecture in READMEs
- Designing complex workflow logic
- Quickly generating Gantt charts for project planning
Frequently Asked Questions
Is my diagram data sent to any server?
No. The Mermaid.js rendering engine runs entirely in your browser. Your diagram code never leaves your computer.
Can I themes the diagrams?
Our playground uses a neutral developer-friendly theme by default, but you can override it using Mermaid.js directives directly in the editor.