Free UML Diagram Maker — Model Classes

See it work

UML diagram examples.

Same tool, four requests. Every drawing below is a real render.

What you type

Create a UML class diagram for public transit route planning with routes, stops, schedules, trips, a Vehicle hierarchy for buses and trains, and a route planner.

Then tryAdd a fare to each Trip.Add a tram subclass of Vehicle.

UML Class Diagram: Transit route planning

UML Class Diagram · OMG UML 2.5.1 §9–§11 · schematex-umlclass

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The drawing

What a UML diagram is.

UML, or Unified Modeling Language, is a standard visual language for describing software. This UML diagram maker creates class diagrams, which show the stable parts of a system: its classes, data, operations and relationships.

A class diagram is useful when the question is what the software is made of. For a time-ordered interaction between objects, a sequence diagram is a different UML diagram type.

Standard: OMG UML 2.5.1 §9–§11
Also follows: ISO/IEC 19505-2:2012 · Classification / Classifiers / Associations
Engine: schematex-umlclass
Editable: Double-click text, drag nodes
Export: SVG · PNG · PDF

UML Class Diagram: What a UML diagram is

Who uses it

Who uses UML diagrams.

Software architects

System models that make services, domain objects and their dependencies visible before implementation.

Product and engineering teams

A concrete model of a feature such as a trip, a booking or a payment that supports planning discussions.

Students

A compact UML example for learning classes, inheritance, interfaces and object relationships.

How it works

How to make a UML diagram in three steps.

Describe it

One paragraph is enough to start.

“Create a UML class diagram for public transit route planning with routes, stops, schedules, trips, a Vehicle hierarchy for buses and trains, and a route planner.”

See the drawing

Drawn by the right engine.

Say what changes

Every edit keeps a version.

Add a fare to each Trip.

V2 · DRAWN FROM V1, NOTHING RETYPED

FAQ

Common questions

What is a UML diagram?

A UML diagram uses the Unified Modeling Language to describe part of a software system. UML includes several diagram types; a class diagram focuses on classes, their members and their relationships.

What kind of UML diagram does this tool create?

This page creates UML class diagrams. Describe the classes, attributes, operations and connections in the system you want to model.

How is a class diagram different from a sequence diagram?

A class diagram shows the static structure of a system. A sequence diagram shows messages exchanged over time between objects or services.

Do I need to know UML notation?

No. You can describe the system in plain language. Knowing terms such as inheritance, composition and multiplicity can help you specify the relationships more precisely.

How do I start a UML class diagram?

Name the main concepts in the system, add the most important data or operations, then state how the concepts relate. Keep the first version focused on one part of the system.

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