🔒 Your diagram never leaves your browser

Live Mermaid Preview

Type Mermaid syntax on the left, see the rendered diagram on the right. Use Examples to load a sample for any diagram type, or paste your own. The render runs locally in strict mode — no server, no surprises.

Ready. Keyboard: Ctrl+Enter Render · Ctrl+S SVG · Ctrl+Shift+S PNG · Ctrl+K Clear · Ctrl+. Examples

What is Mermaid?

Mermaid is a JavaScript library that turns short text descriptions into rendered diagrams. GitHub, GitLab, Notion, Obsidian, Hugo, Jekyll, and many documentation tools render Mermaid blocks automatically, which is why it has become the de-facto "diagrams as code" syntax.

What you can do here

  • Render any of the eleven Mermaid diagram types as you type.
  • Switch themes between default, dark, forest, and neutral.
  • Export the result as SVG (vector) or PNG (raster).
  • Share a URL that encodes the diagram in the fragment — the diagram source never reaches our server.
  • Learn from the per-type guides under Diagrams.

Privacy notes

Rendering runs entirely in your browser. The Mermaid library is bundled from node_modules at build time, not fetched from a CDN at runtime. The "Copy share URL" feature stores the diagram in the URL fragment (#code=...); fragments are never transmitted to the server, so your diagram source is not in our access logs. See our Privacy Policy.