Free online Mermaid diagram viewer and editor with live preview, AI generation, and exports
Stage
Startup
Not given
Founded
2026
Not given
Based in
DE
Not given
Pricing model
Freemium
Freemium
Pricing
Browser: Free. Native app for iPhone, iPad and Mac: €14.99/$12.99 at launch (regular €19.99/$19.99), one-time purchase across all three devices, no subscription.
Free: unlimited editor and preview, 3 saved diagrams, 5 AI uses total, PNG export 1× with watermark. Starter: $6.99/month or $69.90/year; 30 saved diagrams, 500 AI conversations per month, PNG export up to 4× without watermark. Pro: $11.99/month or $119.90/year; unlimited diagrams, unlimited AI, PNG
Key features
Fully offline with no server required
Real folders on disk and Markdown files
Automatic version history with restore
Sync via user's own cloud folder (iCloud, Dropbox)
Nested folders to any depth
Freehand drawing with pen and color
Magnetic arrows for connecting elements
Full-text search across all folders
Interactive to-do lists on canvas
Live preview of Mermaid code as you type
AI diagram generator, editor and syntax fixer
PNG export on every plan; JPG, SVG and PDF on Pro
All 22+ Mermaid diagram types supported
Share diagrams via public links and embeds
Save diagrams to cloud with folders and version history
Keyboard shortcuts and autocomplete
Mobile-responsive editor with pan and pinch-zoom
What makes it different
No account or server: your data never leaves your device
Real files you own: folders are real folders, documents are Markdown files
Works fully offline with no internet dependency
Automatic sync through your own cloud (iCloud or Dropbox)
Native apps for iPhone, iPad and Mac showing full canvas
No account or sign-up required to start editing diagrams
Affordable pricing: Starter at $6.99/month, Pro at $11.99/month
Diagrams render in your browser; nothing stored unless you choose to save
Fast editor with instant rendering and clear error messages
visualOS
Mermaid Viewer