JetUML

At a glance

• Editor score
  6.9 / 10
• Pricing
  Free plan
• Best for
  Free lightweight desktop UML diagrams
• Free plan
  Yes
• Paid from
  Free
• UML diagram types
  class, sequence, state, object, use case
• Facts checked
  22 Sep 2026

• Where it wins

  • Supports class, sequence, state, object, and use case diagrams
  • Automatic edge layout and semantic diagram validation
  • Exports to SVG, PNG, and JPEG and copies diagrams to the clipboard

• Where it doesn't

  • Focused on diagram creation rather than code generation or reverse engineering
  • Does not provide verified team collaboration features
  • Desktop application rather than a centralized model repository

Our verdict on JetUML

JetUML is a free, open-source desktop application for creating software design sketches. It is aimed at developers, students, educators, and teams that need a focused way to create UML diagrams without adopting a larger modeling environment. The supported diagram types include class, sequence, state, object, and use case diagrams. JetUML runs on Windows, macOS, and Linux, making it suitable for cross-platform desktop workflows.

Its feature set centers on fast diagram production and refinement. Automatic edge layout can help organize connections, while semantic diagram validation provides feedback on model structure. Users can duplicate diagrams to explore alternatives, customize the interface with dark mode and font controls, and copy diagrams to the system clipboard. Export supports image formats including SVG, PNG, and JPEG, which fits documentation, presentations, and design discussions. Diagrams are stored as JSON files with documented formats and schemas, so they can be accessed and manipulated outside the application.

JetUML is distributed as Java archives, with a Windows package and community-provided Nix installation options for macOS and Linux. Its open-source, free desktop model is a strong fit for individual diagramming and lightweight software design work. The trade-off is its deliberately narrow scope: code generation, reverse engineering, team collaboration, and a centralized model repository are outside the verified feature set. Choose JetUML when you want portable UML sketching with validation and image export; consider another tool when your workflow depends on shared modeling, repository-based governance, or software engineering automation.

Your product? Our editors can test JetUML in depth and publish a review, labelled as paid · from $149/mo →

JetUML pricing

JetUML fact sheet

Alternatives to JetUML

• IBM Engineering RhapsodyA broad engineering suite for teams connecting models, code, requirements, and verification.9.3
• Sparx Enterprise ArchitectA broad enterprise modeling suite with deep repositories, engineering and versioning features.8.9
• IBM Rational Software Architect DesignerA broad enterprise modeling platform for teams that need traceability and transformation workflows.8.9

See all JetUML alternatives →

Featured on iTechGuides

JetUML is listed in our UML Modeling Software directory. Add the badge to your site — it links back to this page.

<a href="https://www.itechguides.com/products/jetuml/"><img src="https://www.itechguides.com/best/badge/jetuml.svg" alt="Featured on iTechGuides" width="230" height="46"></a>

Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026

Advertiser disclosure: iTechGuides is reader-supported. Vendors can pay for top positions in our rankings and for a place on other products' pages, and we may earn a commission when you click some links. Bought places stand at the number bought; this page and our disclosure say so. Paying vendors may get a fuller, more detailed review from our editors, and that review can change their score. How we rank.

Last updated 7 Oct 2026 · How we research and update