How to Install and Use PlantUML Plugin in IntelliJ IDEA for UML Diagram Creation

PlantUML is an open‑source tool that lets you quickly create UML diagrams using a simple textual language, rendering the graphics via the Graphviz library and exporting them as PNG or SVG files.

Its main advantages are full‑text editing without drag‑and‑drop, platform‑independent operation (only a PlantUML JAR is required), and integration with many editors and IDEs such as IntelliJ IDEA, Eclipse, and Notepad++.

For Java developers who use IntelliJ IDEA, the article walks through installing the PlantUML Integration plugin via File → Settings → Plugins → Search "PlantUML" → Install .

It also covers installing Graphviz on Windows (download the MSI from the official site) and configuring environment variables:

Add a variable GRAPHVIZ_HOME with the installation path, e.g., D:\WorkWare\Graphviz2.38 .

Append %GRAPHVIZ_HOME%\bin to the Path variable (separate entries with a semicolon).

Set GRAPHVIZ_DOT to %GRAPHVIZ_HOME%\bin\dot.exe .

After confirming the installation with dot -version in a command prompt, you configure IntelliJ IDEA to use Graphviz via File → Settings → Other Settings → PlantUML .

To create a diagram, create a new .uml file, write PlantUML code such as:

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

The IDE will render the diagram in real time. You can also generate class diagrams from existing code or use the Chrome extension "PlantUML Viewer" to edit and view diagrams directly in the browser without installing Graphviz.