About Mermaid Theme

Mermaid Theme (mermaidtheme.com) is a free online tool that renders Mermaid diagrams onto an HTML5 canvas with beautiful themes and visual effects.

What it does

• Canvas rendering — Mermaid code is parsed by the official Mermaid.js engine, then drawn onto a high-DPI canvas with smooth zoom and pan.
• Theme presets — restyle your diagram background with one click: Clean White, Warm Paper, Ocean Depth, Forest Calm, and Dark Pro.
• Visual effects — drop shadows, glow, background gradients, grid overlays, and ambient particles.
• High-resolution export — download your diagram as PNG, JPG, WebP, or SVG at 1x, 2x, or 4x resolution, or copy it straight to the clipboard.

Privacy first

Everything runs client-side in your browser. Your Mermaid code and diagrams are never uploaded to any server.

Supported diagram types

All diagram types supported by Mermaid.js work here: flowcharts, sequence diagrams, class diagrams, state diagrams, ER diagrams, Gantt charts, pie charts, Git graphs, mind maps, timelines, user journeys, C4 diagrams, and more.