About Diagramium

Last updated: July 27, 2026

Diagramium is a free diagram editor for sequence diagrams, flowcharts and org charts, made in Canada for the world — for developers, product managers, teachers, analysts and support teams. Draw by dragging participants and messages, or type Alice->Bob: Hello in the built-in text editor and watch the diagram appear. Both stay in sync, so every person on a team can work the way they think.

Principles

• Local-first. No account, no sign-in — diagrams live in your browser and in files you export, and are never uploaded.
• Private. No cookies, no ads, no analytics, no counts — the app collects nothing. See the privacy policy.
• Free. Every diagram type, theme, animation and export, for everyone.
• Portable. Every diagram is also plain text you can paste into chat, tickets or version control.

Who it is for

Diagramium is for anyone: there are no accounts, and no minimum age. Educators and trainers preparing materials for their classes, students and self-learners, and professional teams are all welcome. See the Terms of Use.

Made by DhuRee Labs Inc., Ontario, Canada.

Contact

Questions or feedback? Email admin@dhureelabs.com.