Mermaid Diagram Viewer

Mermaid is a JavaScript-based diagramming language that uses text syntax to generate diagrams. It has become the de facto standard for diagrams in developer documentation, README files, and Markdown-based tools. Its popularity exploded further because AI models like Claude and ChatGPT frequently generate Mermaid syntax to illustrate architectures, workflows, and data models.

Yes. Zolkit's Mermaid viewer uses the latest stable version of mermaid.js (v11), which supports all current diagram types including flowcharts, sequence diagrams, class diagrams, ER diagrams, Gantt charts, state diagrams, mind maps, Git graphs, quadrant charts, timelines, and pie charts.

Absolutely — that's exactly what this tool is built for. When Claude, ChatGPT, Gemini, or any other AI assistant outputs Mermaid code (usually inside a code block), simply copy that code and paste it directly into this viewer. The diagram renders immediately with no extra steps.

You can export as SVG (scalable vector graphic — ideal for documentation, web pages, and anywhere you need crisp lines at any size) or as PNG (a 2× high-resolution raster image suitable for presentations, Word documents, and email). Both exports happen locally in your browser — no upload required.

There is no enforced size limit. In practice, very large diagrams (hundreds of nodes) may render slowly or produce visually cluttered output — this is a Mermaid limitation rather than a tool restriction. For best results, break complex diagrams into smaller focused diagrams.

The most common cause is a syntax error in the Mermaid code. Check that the diagram type keyword (flowchart, sequenceDiagram, classDiagram, etc.) is correct and on its own line. Special characters inside node labels may need to be quoted. The error panel below the preview shows the specific line causing the issue.