Frequently Asked Questions (FAQ)
What's the goal of PlantUML?PlantUML is used to draw UML diagrams, using a simple and human readable text description.
Be careful, because it does not prevent you from drawing inconsistent diagrams (such as having two classes inheriting from each other, for example). So it's more a drawing tool than a modeling tool.
How long do the images generated by PlantUML Server live for?
Links to png or svg generated by PlantUML Server are valid forever (that is as long as the server is up).
However, we do not store any diagrams on our servers. This may sound contradictory. It is not: the whole diagram is compressed into the URL itself. When the server receives the URL, it decompresses the URL to retrieve the diagram text and generates the image. There is no need to store anything. Even if the server is down, you can retrieve the diagram using the flag
It does not work on my config!PlantUML has been installed on various systems, and some users have reported minor issues when installing it.
You can have a look on this page which give advises if something is wrong.
Which version of Graphviz should I use?
You have more information about Graphviz about Graphviz here. The following version have been tested, and are known to work:
Is this mature? I don't see any new release?Google Trends are somehow positive. And there are few books that mention PlantUML. So yes, it's mature. Note that PlantUML is developed with continuous integration in mind. That means that there are new releases quite often, with (hopefully!) backward compatibility. So the file
or use the following small special diagram description:
How to know if a new release is available?
To check if a newer version is available for download, you can go to the download page. You can also subscribe to the following rss flows:
Or use the following small special diagram description:
I have an error message with the Eclipse Plugin.If you have the following error message : The currently displayed page contains invalid values when displaying the Windows/Preferences/PlantUML, you should try to quit Eclipse and use the
I want to generate huge diagrams!
PlantUML limits image width and height to 4096. There is an environment variable that you can set to override this limit:
Another way is an option in the command line:
Note that if you generate very big diagrams, (for example, something like 20 000 x 10 000 pixels), you can have some memory issues. The solution is to add this parameter to the java vm : -Xmx1024m.
I have issues with accented characters.Characters encoding is a subtle thing... By default, PlantUML use the default charset of your platform, which may or may not be UTF-8 . If you want to know which charset you are using, you can type the following command:
If you want to use a different charset, for example UTF-8, you can use the
You can also find here information about unicode . Note that even if Java does not support B.O.M. (Byte Order Mark) in UTF-8 format file, a workaround has been put into PlantUML, so this should not be an issue.
I have issues with Asian characters.
Some Japanese users reported that they have to set the
Since the new architecture, it should simply work, because Java knows how to draw East Asian characters.
How to generate EPS?You can use the
What about XMI?
Work is in progress.
Is @startuml needed in with -pipe flag?Short answer: You do have to use
Under which license is PlantUML distributed?
PlantUML is distributed under the GPL license.
You can print the license using the command line option:
Or you can use the special diagram:
I don't like GPL!You can also use: DITAA for example), but are 100% able to generate UML diagrams. You can print the license of these versions using the command line option:
Or you can use the special diagram:
Are images generated by PlantUML covered by the GPL/LGPL/ASL/EPL/MIT license?
No, they are not. Images (whatever their format : PNG, SVG...) generated by the execution of PlantUML are owned by the author of their corresponding sources code (that is, their textual description in PlantUML language). Images generated by the execution of PlantUML are not considered as covered work. You can do whatever you want with them. The generated images can then be used without any reference to the GPL/LGPL/ASL/EPL/MIT license. It is not even necessary to stipulate that they have been generated with PlantUML, although this will be appreciated by PlantUML team. There is an exception : if the textual description in PlantUML language is also covered by some license (like the GPL/LGPL/ASL/EPL/MIT), then the generated images are logically covered by this license.
Can I redistribute the LGPL binary file PlantUML.jar and if there any constraints about it?As long as you do not modify the Java source code and the jar file, you can integrate PlantUML.jar in your own closed source software. The only constraint is that you have to mention somewhere in your own license or in your documentation that you are using PlantUML and that PlantUML is distributed under LGPL. You can then even sell your software and earn money, without any other constraints (although donation will be appreciate in that case
What is the license of the PlantUML syntax?
There are no license for the PlantUML syntax itself : this means that everybody can use it. So you can use PlantUML comments into your own code : those comments are owned by yourself, and are not considered as covered work, and are not covered by the GPL/LGPL/APL/EPL/MIT license. Only the current implementation (that is, PlantUML program) is licensed under GPL, LGPL, ASL, EPL or MIT. On the other hand note that the documentation (examples, notices, ...) published in the PlantUML website is copyrighted. But you can still write your own documentation.
What does EmptySvgException mean?PlantUML is using Graphviz to generate some diagrams. So PlantUML is launching dot program and retrieve the information generated by dot as a SVG flow. This message means that PlantUML is getting an empty flow from dot execution, and therefore cannot generate UML diagrams. There may be several reasons why this happens:
Could not initialize class net.sourceforge.plantuml.ugraphic.UFont
If you have the error message
I have a message complaining about X11 or headless!If you are running PlantUML on a linux server without graphical capability, you may have some error message:
I have an UnsatisfiedLinkError under Mac OS X!
Under Mac OS X, if you have some error message like:
You need to follow the instructions on http://stackoverflow.com/questions/25914757/osx-yosemite-jvm-shared-library-does-not-contain-the-jni-createjavavm-symbol:
PlantUML scripts are grabbing keyboard/window focus!Depending on your configuration, you can try the flag
I found an issue, but I cannot provide my diagram showing the issue because my diagram contains confidential dataThere is a
I have a question that is not here!You can use the forum facility. Someone will try to answer your question there.