GraphViz is a software that provides a program called dot. This dot program is able to generate a directed graph from a textual description. Depending on diagrams you want to generate, PlantUML needs a working version of GraphViz to be able to generate the following diagrams:
For all other diagrams, GraphViz is not needed nor used.
Installation under Windows
Starting from 1.2020.21
If you use a recent version (that is at least version 1.2020.21), you don't need to manually install GraphViz anymore ! A minimalistic graphviz dot.exe is packed into PlantUML and will be automagically unzipped in some temporary folder if needed (that is, if no installed GraphViz is available). This is really the prefered option under Windows.
Older PlantUML versions
For older version, you have to install GraphViz by yourself. You can either:
With x64 version, you may have to run dot -c (with with Administrator Right) in a command line to finalize the installation, like in the following example: To retrieve dot.exe, PlantUML scans your c:\ drive and search for c:\*\graphviz*\bin\dot.exe or c:\*\graphviz*\release\bin\dot.exe. This is not recursive: you have to use a folder at root level. Another option is that you specify the environment variable GRAPHVIZ_DOT to set the exact location of your GraphViz executable.
You can also build it from the source. If you do, you have to build it with libexpat in order to work with PlantUML. By default, the dot executable is expected:
Firstly in: /usr/local/bin/dot
Then in: /usr/bin/dot
You can also specify the environment variable GRAPHVIZ_DOT to set the exact location of your GraphViz executable.
Installation under Mac
You can easily install GraphViz by installing brew on your Mac machine. This could fix issues if you have installed GraphViz as .dmg package.
brew install libtool
brew link libtool
brew install graphviz
brew link --overwrite graphviz
By default, the dot executable is expected:
Firstly in: /usr/local/bin/dot
Then in: /usr/bin/dot
You can also specify the environment variable GRAPHVIZ_DOT to set the exact location of your GraphViz executable.
Testing
To have information about where PlantUML expects to find dot, you can use the command line:
java -jar plantuml.jar -testdot
You can also use this special diagram description:
@startuml
testdot
@enduml
Try to launch dot command into a command shell. You may have to finalize the installation by typing dot -C. You can also specify the environment variable GRAPHVIZ_DOT to set the exact location of your GraphViz executable.
Important note about version
The following GraphViz versions have been tested, and are known to work:
Hitchhiker's Guide
To retrieve 