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Java Class Diagram Generator

Produce a class diagram for Java-oriented models: classes, interfaces, and inheritance. Adapt the starter to your packages, then export for README or design review.

Features

  • Live editor for java class diagram generator
  • Starter template included on the page
  • PNG and SVG export
  • No install required

Need a blank canvas? Open the full UML studio.

What you can model

Java teams often need diagrams for entities, services, and interfaces. Visibility, abstract types, and realization map cleanly to UML class notation for design and onboarding docs.

How to use this generator

Rename types to match your code, show interfaces with realization, keep one package story per diagram, preview, then export PNG or SVG.

Notation that matters

Use interface for Java interfaces and abstract class for abstract types. Realization and inheritance arrows should match implements and extends. Field and method visibility should reflect your public API surface.

Keep the diagram readable

This page does not upload a repository. Translate only the types that matter so the diagram stays intentional. Use the general class diagram maker for language-agnostic models, and the Python page when the codebase is Python.

Frequently asked questions

Is this Java class diagram generator free?

Yes. Create and export online without a subscription.

Can I paste a full .java file?

Prefer a simplified model of the types you want stakeholders to see. Large pastes create noisy diagrams.

How is this different from the class diagram maker?

This page uses Java-oriented starters and wording. The class diagram maker is the general tool for any domain model.

Related tools

Browse the full UML diagram tools directory or return to the UML diagram hub.