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With our UML software, you can create and share a class diagram, sequence diagram, or any UML model

create, share, and collaborate with our free uml software:

  • Use case diagram
  • Class diagram
  • Object diagram
  • State diagram
  • Activity diagram
  • Sequence diagram
  • Collaboration diagram
  • Component diagram
  • Deployment diagram
  • See UML diagram examples

It's easy to model UML (Unified Modeling Language) with this free UML software. Just drag and drop from a library of shapes to show any of the nine UML diagrams needed to model a system. Since no single diagram can model a system completely, the free UML diagram editor makes it easy to add more diagrams as you need them.

See more uml examples

Our UML Editor Makes it Easy

Show structural (static), behavioral (dynamic) and implementation characteristics—the shape and connector libraries in the free UML diagram software make it easy.

A class diagram tool, sequence diagram tool, and all around free UML diagram tool all-in-one, Gliffy enables you to combine a class diagram, sequence diagram, or any combination of UML diagrams to show a design view, process view, component view, deployment view, or use case view with ease.

Collaborate with Anyone

Our free online uml software enables you to share and collaborate on your class diagram, sequence diagram, or other UML diagram with others, regardless of PC platform, and without having to install anything.

How to use a UML diagram

Unified Modeling Language, or UML diagrams, are a standard language used to depict the requirements, analysis, design, and implementation of a system. The language consists of nine diagram types that can be combined to model a system at any point in its lifecycle. In a UML diagram, shapes, connectors, and numbering is used to show the relationships between objects and characteristics of the system.

UML Diagram Types include:

  • Use case diagram
  • Class diagram
  • Object diagram
  • State diagram
  • Activity diagram
  • Sequence diagram
  • Collaboration diagram
  • Component diagram
  • Deployment diagram

A few of our customers

Gliffy has customers in over 40 countries. Gliffy customers include personal users, small businesses, academia, and leading global corporations, who are embracing the benefits of communicating visually. They are creating, sharing, and collaborating across time and distance, vastly improving clarity, efficiency, and decision making.