About Diagramgen

What this site is

Diagramgen is a set of free text-to-diagram tools: type a description and get a rendered diagram. There are generators for flowcharts, sequence diagrams, ER models, UML class diagrams, mind maps, Gantt charts, architecture, network, state, activity and supply chain diagrams. Every page loads with a real, editable example, and the examples gallery collects more you can load into the editor with one click.

How it works

All rendering runs locally in your browser using the open-source Mermaid.js engine — the text you type, and the diagram it produces, never leave your device. The first render downloads the engine once from a public CDN and caches it; after that, conversion and export happen entirely on your machine. You can export a vector SVG or a PNG, copy the Mermaid source, or copy a Markdown block that renders directly in a GitHub README. Flowchart tools also accept a plain indented outline, so no Mermaid syntax is required to get started.

Why it's free

Because rendering happens on your device, running this site costs little more than static hosting — there is no per-diagram compute bill to pass on. There are no ads and no trackers; some pages link to related free tools we operate, and those links carry only a simple source tag so we understand traffic between our own sites.

Who's behind it

Diagramgen is built and maintained by a small independent team that makes free, no-signup browser tools. Questions, corrections or feedback: support@diagramgen.app.

Data and policies

There is no account, no signup and no watermark, and analytics are cookieless and anonymous. The details are in the privacy policy; usage rules are in the terms.