Common commands


Everything that starts with simple quote ' is a comment.

You can also put comments on several lines using /' to start and '/ to end.

Footer and header

You can use the commands header or footer to add a footer or a header on any generated diagram.

You can optionally specify if you want a center, left or right footer/header, by adding a keyword.

As for title, it is possible to define a header or a footer on several lines.

It is also possible to put some HTML into the header or footer.

Alice -> Bob: Authentication Request

<font color=red>Warning:</font>
Do not use in production.

center footer Generated for demonstration

put header in a UML diagram


You can use the scale command to zoom the generated image.

You can use either a number or a fraction to define the scale factor. You can also specify either width or height (in pixel). And you can also give both width and height : the image is scaled to fit inside the specified dimension.

  • scale 1.5
  • scale 2/3
  • scale 200 width
  • scale 200 height
  • scale 200*100
  • scale max 300*200
  • scale max 1024 width
  • scale max 800 height
scale 180*90
Bob->Alice : hello
scale in or out UML diagram


The title keywords is used to put a title. You can add newline using \n in the title description.

Some skinparam settings are available to put borders on the title.

skinparam titleBorderRoundCorner 15
skinparam titleBorderThickness 2
skinparam titleBorderColor red
skinparam titleBackgroundColor Aqua-CadetBlue

title Simple communication\nexample

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

using title in UML diagram
You can use creole formatting in the title. You can also define title on several lines using title and end title keywords.

 <u>Simple</u> communication example
 on <i>several</i> lines and using <back:cadetblue>creole tags</back>
end title

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

example of colored title in UML diagram


There is also a caption keyword to put a caption under the diagram.

caption figure 1
Alice -> Bob: Hello

put caption in UML diagram

Legend the diagram

The legend and end legend are keywords is used to put a legend.

You can optionally specify to have left, right or center alignment for the legend.


Alice -> Bob : Hello
legend right

put a legend in UML diagram