UML Sequence Markup

Create and edit your sequence diagrams by entering text.

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  1. Activate the UML shape library. To do this, press “More Shapes” on the bottom left of the Editor, use the hotkey “M”, or start a new document from a UML template.
  2. Under the “UML Sequence” category in the left toolbar, click “Use Markup.”

  3. In the pop-over, type your markup.
  4. Click "Build" when you are ready to generate the diagram.

  5. To edit the markup of a diagram that you have already built, simply click on the diagram and the pop-over will appear on the left side of the Editor.
  6. To create a new diagram, click "Use Markup" again. 

We currently support the following markup, provided by  PlantUML, and will add more markup types as the need arises. Please if you are looking for a specific type of UML sequence markup that we do not currently support.

  • To draw a message between two participants, use
    • -> for a solid line (Alice->Bob)
    • --> for a dotted line (Bob-->Alice)
  • To add a label to messages between participants, use : label.
    • Alice->Bob: label
  • If you would like to include a line break in the text, you can use a \n to break the label.
    • Alice->Bob: text\nTest
  • To add comments on messages, use a single apostrophe (‘) to start the comment. (Note: Contractions in labels are not currently possible for this reason.) You can put comments on multiple lines by using /’ to start and ‘/ to end.
  • You can list out the participants and give them aliases. Put each participant on a new line using the format below:

Participant a as Alice

Participant b as Bob

  • Participants and messages can only be one word long unless they are inside quotation marks:

Participant a as “Alice Jones”

  • A message to self is supported by simply using Alice->Alice
  • We support three arrow styles at the moment:
    • Closed arrow: ->
    • Open arrow: ->>
    • No arrow: -
  • To label a grouping, type “opt label” on a new line. To include text in the grouping, continue onto the next line and enter the text to go inside the label. On a third line, type “end.”

Opt label

Alice->Bob: this other text


  • Can I re-edit my sequence diagram’s markup after closing the markup dialogue? Yes, you can do this as long as you have not manually adjusted or ungrouped the diagram on the canvas. To re-open the dialogue box, simply select the diagram and the pop-over panel will open in the left toolbar for you to re-edit the diagram’s markup.
  • How can I style my sequence diagram? Select the sequence diagram and use the top options bar to style your diagram. If you would like to style individual blocks/elements on your diagram, you must first ungroup the diagram by doing the following: select the diagram > right-click > Ungroup. Note: Ungrouping means you will not be able to re-edit the markup.


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