Yes, 100% free. No signup, no paywall, no usage limits. Forever.
Mermaid is a text-based diagramming language that lets you create flowcharts, sequence diagrams, and more using simple markdown-like syntax. Write graph TD; A-->B and get a visual diagram.
MermaidView renders flowcharts (graph/flowchart syntax) with subgraphs, custom styling and all node shapes, plus state diagrams (stateDiagram-v2), entity-relationship diagrams (erDiagram) and class diagrams (classDiagram). Sequence and gantt diagrams are on the roadmap.
Click the PNG or SVG button in the export toolbar above the preview, or open the command palette (Cmd/Ctrl+K) for WebP and PDF export. You can choose a dark, light, or transparent background before exporting.
Your diagram content never leaves your browser — nothing you type is sent to a server, and there is no account or cloud storage. Like most sites we use anonymous, aggregate analytics (page views only) to understand traffic, but it never has access to your diagrams. Your code stays completely private.
Yes. After your first visit a service worker caches the whole app (including the code editor and fonts, which are all served from our own domain), so it keeps working with no internet connection — and all diagram processing already happens locally in your browser.
Any modern browser works: Chrome, Firefox, Safari, Edge. Mobile browsers are also fully supported with a responsive interface.
MermaidView offers interactive draggable nodes, animated gradient edges, 14 node shapes, ELK hierarchical auto-layout, three selectable themes plus a custom theme builder, a command palette, and instant PNG/SVG/WebP/PDF export with background options — all in a cleaner, more visual interface.
Yes. Click Share to copy a link with the entire diagram encoded in the URL — no account or server needed. You can also export a high-quality PNG, SVG, WebP, or PDF image, or open the /embed view for a chrome-free read-only render.
MermaidView is free for everyone with no signup and no limits. Your diagram content runs entirely in your browser and never leaves your device.