Boost Your UML Workflow: Install and Use PlantUML in IntelliJ IDEA

What is PlantUML

PlantUML is an open‑source project that enables fast creation of UML diagrams. It defines a complete textual language for describing UML relationships and uses the powerful Graphviz rendering engine to generate images, SVG files, and other formats.

Advantages of PlantUML

Fully text‑based editing, no drag‑and‑drop controls, automatic layout, simple and attractive output.

Independent of any development platform; as long as the PlantUML JAR is available, diagrams can be generated.

Integrates with many editors and IDEs such as IntelliJ IDEA, Eclipse, Notepad++, etc.

Install PlantUML plugin in IntelliJ IDEA

Open File → Settings → Plugins , search for PlantUML integration , and install the plugin.

Install Graphviz

Download the Windows installer from the official site:

https://graphviz.gitlab.io/_pages/Download/windows/graphviz-2.38.msi

After installation, add environment variables: %GRAPHVIZ_HOME%\bin and set GRAPHVIZ_DOT to:

%GRAPHVIZ_HOME%\bin\dot.exe

Verify Graphviz installation

Open a Windows command line and run dot -version. If version information is displayed, the configuration is correct.

Configure Graphviz in IntelliJ IDEA

Navigate to File → Settings → Other Settings → PlantUML and set the path to the Graphviz executable.

Create diagrams with PlantUML

Create a new .uml file in the project and write PlantUML code. The plugin renders the diagram in real time.

@startuml
Alice -> Bob: Authentication Request
Bob --> Alice: Authentication Response

Alice -> Bob: Another authentication Request
Alice <-- Bob: another authentication Response
@enduml

The right pane shows the generated diagram instantly.

You can also generate class diagrams from existing code, similar to the "IDEA one‑click UML" feature.

Alternative: PlantUML Viewer Chrome extension

If you prefer not to install Graphviz, you can use the PlantUML Viewer Chrome extension. After installing, you can edit PlantUML text in the browser and see the rendered diagram instantly.