With our sequence markup tool, you can create and edit sequence diagrams with ease. Since Lucidchart auto-generates a sequence diagram from the text you enter, you can use the time you save to return to your code… or watch Star Wars.

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Watch: UML class diagrams

Create a sequence diagram with markup

Follow these steps, and Lucidchart will auto-generate a sequence diagram for you:

Activate the UML shape library.
- Click More shapes at the bottom of the Shape menu on the left side of your document or press "M" on your keyboard.
- In the "Shapes" tab, check the box for the “UML” shape library.
- Click Use selected shapes.
Under the “UML Sequence” shape library in the Shape menu, click Use Markup.
In the pop-over on the left-hand side, type your markup.
Click Build when you are ready to generate the diagram.

To create a new diagram, click Use Markup in the UML Sequence shape library again.

Supported markup

Category	Syntax	Description
Lines	Alice -> Bob Alice <- Bob	Draw a solid line (you can draw lines in both directions).
	Alice -->	Draw a dotted line.
	Alice -> Alice	Draw a solid arrow to and from a participant.
Lifelines	activate Alice	Start participant activation with lifeline.
Lifelines	deactivate Alice	End participant activation ending the lifeline.
Arrows	->	Close arrow
	-> >	Open arrow
	-	No arrow
Text	Alice->Bob: text	Add a label to messages between participants.
Text	Alice->Bob: text\nmore	Add a label with a line break between participants.
Notes	note left of Alice: text1	Add a note shape on the left of Alice (if there are only two characters, "of Alice" could be omitted).
	note right of Alice:	Add a note shape on the right of Alice.
	note over Alice: text3	Add a note shape displayed over Alice.
	note over Alice, Bob:	Add a note shape displayed over Alice and Bob.
	note over Bob, Alice: This is an example of a long note \n with a line break. (keep this all in one line)	Add a note shape with multiple-lined notes, displayed over Alice and Bob.
Grouping	alt successful case Bob -> Alice: data accepted else some kind of failure Bob -> Alice: data rejected end	Build a grouping message with "alt" (alternative) and "else" to show different situations.
Grouping	opt text1 Alice -> Bob: text2 end	Build a grouping message with the keyword "opt." You can change "opt" to other keywords as well. We support four key words in this pattern: - opt (means "optional") - par (means "parallel") - loop - critical Note: These four keywords don't support "else." Only the keyword "alt" can be paired with "else."
Alias	participant A as Alice	Give participants aliases so you can write faster.
Alias	participant A as "Alice Jones"	Put quotation marks around alias to give participant an alias longer than one word.
Comments	'comment text	Single line comment
Comments	/' comment text '/	Multiple line comment

Edit a sequence diagram

Don’t worry if your sequence diagram isn’t perfect on the first try. You can still edit the markup of a diagram you have already built, as long as you have not manually adjusted or ungrouped the diagram on the canvas.

Simply click on the diagram, and the sequence markup dialogue will appear on the left side of the editor.

Style a sequence diagram

Select the sequence diagram, and use the Properties bar at the top of the editor to style your diagram. If you would like to style individual blocks/elements on your diagram, you must first ungroup the diagram. Select the diagram, right-click, and select Ungroup.

Note: If you ungroup your diagram, you will not be able to edit the markup again.

Resources

To learn more about this feature, explore the additional resources below. These resources are available in English only.

Videos

UML class diagrams | Tutorial

UML use case diagrams

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