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PlantUMLAstah Professional
Free

Free and open source under the GPL.

 Paid

Commercial license with a free trial and student options.

Windows, macOS, Linux, Web, Command line macOS
  • Covers far more diagram types than most text-based tools
  • Integrations for nearly every editor, wiki and documentation system
  • UML, ERD, DFD and flowcharts in one tool
  • API and free plugins for customisation
  • Requires Java and, for some diagram types, Graphviz
  • The syntax is inconsistent between diagram types
  • Paid license after the trial
  • Focused on software modelling rather than general diagramming
Downloadable app, Web application Downloadable app
Open source Closed source
License: GPL-3.0 License not stated
Not stated if an account is needed Not stated if an account is needed
Not stated if it works offline Not stated if it works offline

Checked September 22, 2026

Checked October 2, 2026

Catalog facts only. Anything “not stated” is unconfirmed. Check full listings for details.