Online Mermaid Diagram Viewer & Editor — Flowcharts & Sequences (Free)
Render & Edit Mermaid Diagrams to SVG Online. Render, edit, and export Mermaid.js flowcharts, sequence diagrams, and architecture blueprints directly to SVG in your browser.
What is Mermaid Viewer and what does it do?
The Mermaid Diagram Live Viewer is a client-side architecture and flowchart renderer that compiles Mermaid syntax into clean, scalable SVG vector graphics.
Create, edit, and preview flowcharts, sequence diagrams, state diagrams, and system architecture maps without installing node CLI packages or graphviz.
- Render flowcharts (graph TD, LR) and sequence diagrams live in real time.
- Pan and zoom large diagrams smoothly without raster pixelation.
- Built-in architecture, authentication sequence, and data pipeline templates.
- Export crisp vector SVG files for documentation and wikis.
How does Mermaid Viewer work?
Parses Mermaid syntax blocks, extracts nodes, directions, and edge relationships, and constructs a responsive SVG scene graph with interactive pan and zoom controls.
100% private: all processing happens locally in your browser using client-side WebAssembly, WebCrypto, WebAudio, and HTML5 Canvas. Your files are never uploaded to any server.
Who needs Mermaid Viewer?
Software Architects & Engineers
Draft system sequence diagrams and cloud architecture workflows for technical specs.
Technical Writers
Generate high-resolution SVG diagram vectors for user manuals and documentation sites.
Supported file formats
Mermaid Diagram Live Viewer opens and processes the following file extensions directly in your browser:
.mmd.mermaid.flowchartHow to use Mermaid Viewer — step by step
- 1
Paste or Open .mmd
Load your Mermaid file or paste diagram syntax.
- 2
View Live Diagram
The vector canvas renders nodes, paths, and lifelines in real time.
- 3
Export SVG
Download crystal-clear vector SVG artwork for documentation.
Frequently asked questions
Which diagram types are supported?
Supports flowcharts (graph TD, LR), sequence diagrams, and architecture maps.
Can I customize the diagram layout?
Yes, you can edit labels, directional flow, and connections live in the editor.
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