Mermaid Editor — Live Diagram Editor Online
Write Mermaid diagram syntax and see a live rendered preview. Supports flowcharts, sequence diagrams, Gantt charts, class diagrams, state diagrams, and ER diagrams. 100% client-side — your diagrams stay private.
How to Use the Mermaid Editor
- Write Mermaid syntax in the left textarea, or click a template button to load a sample.
- Click Render to generate the diagram in the preview pane.
- The diagram renders using Mermaid.js directly in your browser.
- Click Download SVG to save the diagram as a vector image.
- Use the template buttons for quick starts: flowchart, sequence, Gantt, class, state, or ER.
Why Use This Mermaid Editor
Mermaid is a popular Markdown-like syntax for creating diagrams, but most editors require installation or a web service. This tool lets you write and preview Mermaid diagrams instantly in your browser.
With six diagram templates, live preview, and SVG export, it's ideal for documentation, presentations, and quick architectural sketches.
Frequently Asked Questions
The editor supports flowcharts, sequence diagrams, Gantt charts, class diagrams, state diagrams, and entity-relationship (ER) diagrams using Mermaid.js syntax.
No. Mermaid.js is loaded from a CDN and runs entirely in your browser. No installation or browser extensions are required.
No. All rendering happens locally in your browser. Your diagram code and rendered output never leave your device.
Use Cases
Architecture Diagrams
Sketch system architecture, microservice connections, and infrastructure layouts with flowcharts.
Project Planning
Create Gantt charts for project timelines, milestones, and task dependencies.
API Documentation
Draw sequence diagrams to illustrate API request flows and service interactions.
Database Modeling
Design entity-relationship diagrams for database schemas and data models.