What is Mermaid?
Mermaid is an open-source diagram-as-code language: you describe boxes, steps and connections in readable text. It supports flowcharts, sequence diagrams, entity relationship diagrams, Gantt charts and mind maps. Templates help you get started.
Export editable diagrams
Download a crisp scalable vector (SVG), or a PNG image. Keep the source text so you can edit the diagram later. Changes are rendered entirely on your device, without accounts or external rendering APIs.
Safe previews
The editor uses strict diagram security settings, disables click actions and does not load remote content. Malformed or unsupported syntax gives an error; simplify the source or try a built-in example. Very large diagrams may strain your device.
Are my files uploaded?
No. Diagrams are rendered with JavaScript and WebAssembly running in your browser tab. Your files are read from your device and the results are created on your device; nothing is sent to gratistools.be or anyone else, which is also why there are no queues, daily limits or watermarks. See the privacy page.
Frequently asked questions
Is this tool free?
Yes. The core tool is free to use in your browser.