Structural UML
Composite Structure Diagram Maker
Model the inside of a complex class or component when a black-box view is not enough. Adapt the starter parts to your design, then export for detailed notes.
Features
- Live editor for composite structure diagram maker
- 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
Composite structure diagrams show internal parts and how they collaborate inside one classifier. Use them for detailed design of a complex service or component that a flat class list does not explain.
How to use this maker
Identify the enclosing classifier, list collaborating parts, connect collaborations with clear labels, preview, then export for design notes.
Notation that matters
Parts sit inside or relate to the enclosing classifier. Connectors show collaboration paths. Ports appear when interaction points on the boundary matter. Keep names aligned with the class or component model.
Keep the diagram readable
Prefer a component or class diagram for system-wide structure. Reserve this view for one classifier at a time. If the story is message order, switch to a sequence diagram.
Frequently asked questions
Is this composite structure diagram maker free?
Yes. Edit and export online without a paid plan.
Is this the same as a component diagram?
No. Component diagrams emphasize larger software units. Composite structure focuses on internals of one classifier.
When is this overkill?
When a simple class diagram already shows the collaboration clearly. Use composite structure only when internal parts need their own picture.
Related tools
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- Sequence Diagram MakerDraw a sequence diagram for auth flows, service calls, and feature interactions. Start from the temp…
Browse the full UML diagram tools directory or return to the UML diagram hub.