Our take: Type a few lines of text and get a flowchart. No account, and your diagram code stays in the URL instead of being sent to a server.
- ✓ No sign-up
- ✓ Diagram never sent to a server — verified
- Requires learning Mermaid syntax
- ! Share links contain the whole diagram
- ? China access — not tested yet
Our test
Tested 28 Sep 2026 · Chrome desktop · 6-line flowchart (5 nodes)
How we checked privacy: we loaded a diagram through the URL and watched the network log. Apart from app files and one analytics ping (p.mermaid.live), no request carried the code. The diagram is compressed after the # in the address, a part browsers never send to servers.
Data sheet
Every row shows how we know it
| Price | Free, open source Tested + official |
|---|---|
| Sign-up | Not required Tested |
| Diagram processing | In your browser — 0 requests carrying it Tested |
| Where it is saved | In the URL and browser storage Tested + official |
| Diagram types | Flowchart, sequence, Gantt, ER, mindmap and ~20 more Tested |
| Promotions | Banner for the paid Mermaid Chart editor Tested |
| Access from China | — Not tested |
When to use it
Quickly draft and edit flowcharts or sequence diagrams as text for docs and READMEs.
Before you use it
A share link contains the full diagram, so export sensitive architecture diagrams as images instead of sharing the link.
How to use it
- Open mermaid.live and type Mermaid syntax in the Code panel
- Check the live preview on the right
- Download PNG/SVG from Actions or copy a link
Alternatives
- draw.io — drag-and-drop diagramsOn-device
- Excalidraw — hand-drawn style whiteboardOn-device
Last verified 28 Sep 2026 · Found something outdated? Tell us. · Mermaid Live Editor official repository