JSON LAB / BROWSER TOOLS
Mermaid Diagram Viewer
Paste Mermaid code and see a rendered flowchart, sequence diagram, or other diagram types instantly. Supports export to SVG or PNG.
What you can do
- Live preview as you type — no submit button needed
- Export rendered diagram as SVG or PNG
- Supports 10+ diagram types: flowchart, sequence, class, state, ER, pie, gantt, and more
- Blueprint dark theme optimized for diagram readability
- 100% client-side processing — your code never leaves your browser
Questions, answered
What diagram types does Mermaid support?
Mermaid supports flowcharts, sequence diagrams, class diagrams, state diagrams, entity-relationship diagrams, pie charts, gantt charts, and more.
Is my Mermaid code sent to a server?
No. All rendering happens locally in your browser using the Mermaid.js library. Your code is never transmitted anywhere.
Why isn't my diagram rendering?
Check the Mermaid syntax. Make sure brackets are balanced, node IDs don't contain special characters, and diagram-specific syntax (like arrows in sequence diagrams) is correct.