Common commands

Comments

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.

@startuml
Alice -> Bob: Authentication Request

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

center footer Generated for demonstration

@enduml

Zoom

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

@startuml
scale 180*90
Bob->Alice : hello
@enduml

Title

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.

@startuml
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

@enduml

You can use creole formatting in the title.

You can also define title on several lines using title and end title keywords.

@startuml

title
 <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

@enduml

Caption

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

@startuml

caption figure 1
Alice -> Bob: Hello

@enduml

Legend the diagram

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

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

@startuml
Alice -> Bob : Hello
legend right
  Short
  legend
endlegend
@enduml

@startuml
Alice -> Bob : Hello
legend top left
  Short
  legend
endlegend
@enduml