Question 1

Do my documents get uploaded?

Accepted Answer

No. Everything is parsed and rendered locally in your browser — opening local files does not even need a network connection.

Question 2

Which diagram languages are supported?

Accepted Answer

PlantUML (sequence, activity, use case, class, state, component, mind map, Gantt) and Mermaid (flowchart, sequence, class, pie and more), plus KaTeX math formulas.

Question 3

What can I export?

Accepted Answer

Single diagrams as SVG / PNG / JPG / PDF; whole documents as standalone HTML or print to PDF.

Question 4

Do I need to sign up or install anything?

Accepted Answer

It is free and requires no account — just open it. You can also install it as a desktop app for offline use.