Mermaid Editor
Diagrams from text · saved in this browser
Draw diagrams from text, free
Write Mermaid code, or paste it from ChatGPT or Claude, and see the diagram as you type: flowcharts, sequence diagrams, Gantt charts, mind maps, ER diagrams and more. Copy it as an image for Docs or Slack, or download PNG, SVG or PDF. No sign-up: diagrams are saved in this browser.
Key facts
- Supports every Mermaid 11 diagram type, including flowcharts, sequence, class, state, ER, Gantt, mind map, timeline, Sankey and C4 diagrams.
Frequently Asked Questions
Is my diagram saved?
Yes, automatically, in this browser only. Nothing is uploaded unless you create a share link. Diagrams don’t sync to other devices, and clearing site data deletes them, so download a copy (Export → Download .mmd file, or More → Download all as .zip) of anything you want to keep. Each diagram keeps a version history you can restore from.
How do I put a diagram into Google Docs or Slack?
Use Export → Copy image, then paste. If your browser can’t copy images, use Download PNG and insert the file. The Background option chooses white, transparent or the theme’s own colour.
Can I paste Mermaid code from ChatGPT or Claude?
Yes. Paste the whole answer, including the ```mermaid fence: the editor strips the fence and renders the diagram. If it doesn’t render, the Problems panel shows the line, and Copy for AI copies the error with your code so you can ask for a fix.
Which diagram types are supported?
Everything Mermaid 11 supports: flowcharts, sequence, class, state, ER, Gantt, pie, user journey, git graph, mind maps, timelines, quadrant charts, Sankey, XY charts, block, architecture, requirement, C4, packet, kanban, radar, treemap and fishbone diagrams. Templates has a starting point for each, and Insert offers the right shapes and arrows for the type you are writing.
Can I present diagrams or undo a big change?
Yes. Present (⇧⌘↵) shows the diagram full screen, and the arrow keys move between the diagrams in the same folder. Version history keeps snapshots as you edit and whenever you press ⌘S; restoring one keeps your current version too.