A free online Mermaid editor — no signup. Write Mermaid text and render a flowchart from text, a sequence diagram, class, ER, gantt or mindmap, live. It's a real-time collaborative Mermaid live editor: share the board URL and everyone edits the same diagram together, with server-side SVG rendering.
Click the button above and you land on a fresh board with this flowchart already rendered. Edit the Mermaid source in the text node and the diagram re-renders — swap flowchart TD for sequenceDiagram, classDiagram, erDiagram, gantt or mindmap and keep going. This is the exact source the editor opens with:
flowchart TD
A[Start] --> B{Decision}
B -->|Yes| C[Do this]
B -->|No| D[Do that]
C --> E[Done]
D --> EsequenceDiagram, classDiagram, erDiagram, gantt or mindmap for a different diagram type.| Capability | Typical Mermaid Live Editor | cnvs.app Mermaid editor |
|---|---|---|
| Renders Mermaid from text | Yes | Yes — flowchart, sequence, class, ER, gantt, mindmap |
| Real-time collaboration | No — single player | Yes — share a URL, edit the same diagram live |
| Signup required | Varies | No — anyone with the URL |
| Shareable result | Copy out an image / paste code | Live board URL, always up to date |
| Server-side SVG render | Client-only in the browser | Yes — rendered server-side to SVG |
| AI can read & edit the source | No | Yes — public MCP endpoint at https://cnvs.app/mcp |
| Mix with sketches & notes | No — diagram only | Yes — sticky notes, freehand, images on the same canvas |
| Price | Free | $0 forever |
Yes. The Mermaid editor on cnvs.app is free with no signup. Open the editor, write Mermaid text, render a diagram, and share the URL — no account, no paywall.
Flowcharts, sequence diagrams, class diagrams, state diagrams, ER diagrams, gantt charts, mindmaps, user journeys, timelines, gitgraph and C4 — all rendered live from Mermaid source text.
The typical Mermaid Live Editor is single-player: you edit alone and copy out an image. cnvs.app is real-time collaborative — anyone with the URL edits the same board live — renders the diagram server-side as SVG, and exposes an MCP endpoint so AI agents can read and edit the source too.
Yes. Share the board URL and everyone who opens it joins the same live canvas. Edits to the Mermaid source re-render for every connected collaborator in real time, with no accounts required.