Mermaid Diagram Composer

Architecture diagrams belong in your repo, not in a proprietary SaaS tool. The Mermaid Diagram Composer lets you write diagrams as plain text and see them rendered in real time, entirely in your browser.

Key Features

• Live Preview: The rendered diagram updates automatically as you type, with a short debounce to keep things smooth.
• Diagram Type Templates: Switch between Flowchart, Sequence, Entity-Relationship, Class, Gantt, and State diagrams with one click — the editor loads a sensible starting template for each.
• Export as SVG: Copy the raw SVG markup to clipboard, or download it as a .svg file ready to embed or commit to your repo.
• Syntax Error Feedback: When your Mermaid syntax is invalid, a clear inline error message tells you what went wrong.
• Local Rendering: All processing happens in your browser via the Mermaid.js library. Your diagram code is never transmitted to a server.

[!TIP] Paste your diagram code directly into a GitHub Markdown file using a ```mermaid fenced code block — GitHub renders it natively, no image needed.