Mac Sequence Diagram makes it incredibly easy to create UML 2.0 style sequence diagrams, using nothing more than plain text (and a sprinkling of emoji).

It supports :-

• Participants
• Participant Boxes
• Signals
• Nested Interaction Frames
• Nested Activation Boxes
• Found signals
• Lost signals
• Multiple signal arrow line styles
• Multiple signal arrow head styles
• Export PDF
• Export PNG
• Export SVG
• Export via the Command Line
• Syntax Highlighting
• Error highlighting
• Canvas zoom up to 14x
• Detachable & collapsable editor
• Light & Dark modes
• Keyword Auto-Completion
• Participant name Auto-Completion
• Version Control Friendly File Format

And so much more.

Feedback, issues and suggestions are welcomed.


What’s New

Version 1.8.5

* Adds support for Apple Silicon CPUs.
* Adds support for async signal arrow heads (see Help documentation, page 8).
* You can now tap interaction frame divider lines, to highlight the associated declaration in the diagram text.
* Adds support for Interaction Frame dividers using 3 dashes (---), which render a dashed line between signals in an Interaction Frame (see "New with Example [OPT+CMD+N]")
* Minor improvements to Participant HUD.
* Adds “Shows Participant HUD” menu option, to present the participants in an overlay, when the topmost participants are no longer entirely visible.
* Fixes a rare crash seen when the syntax highlights are applied.
* Fixes a defect where interaction frames containing only signals to self, would render incorrectly.
* Fixes a defect where reversed signals would always render with a solid signal line.
* Updates acknowledgments - removing Crashlytics.

Other recent enhancements :-
* Updated to use Microsoft AppCenter for crash reporting and analytics.
* Adds support for copying the diagram into the paste buffer as an SVG.
* Adds “#style-reset” keyword, to resume default styling for elements that follow.
* Adds an indicator beside auto-completion suggestions, do distinguish keywords from user strings.
* Adds support for placing self-signal message label on right OR left of signal arrow.
* Adds support for Ref interaction frames (see Help documentation, page 14)
* Minor improvements to auto-completion behaviour.
* Adds support for custom vertical spacing above Dividers, Interaction Frames, Notes and Signals (see Help documentation, page 25)
* Adds support for dividers with no label.
* Fixes a defect where having a lifeline destruction marker on the left could cause a signal to not be rendered.

A massive thank-you for all the feedback and suggestions (and bug reports!).

Please keep ‘em coming and don’t forget to rate and/or review.

Thanks again for your valued support.

-- Mike

Ratings and Reviews

4.8 out of 5
126 Ratings

126 Ratings

Rlatic ,

Really good, just one annoying missing feature

Been looking for a while for something like this to generate sequence diagrams. Everything I was using before was like Gliphy, which made one drag/drop graphics, drag items to expand them, etc, which is a pain. This app lets me, a programmer, create sequence diagrams programatically with a DSL, which greatly increases productivity. These diagrams can then be exported to images or PDFs for sharing, or by the save file for collaboration.

The only thing that this app is missing (which I was debating a 4-star review bescause of, because it is annoying and potentially problatic for larger diagrams with frequent edits), is that one cannot highlight multiple lines and hit 'tab' to increase the indentation. Doing so results in behavior like TextEdit, where the highlighted text is deleted and replaced with a tab character. Not sure if this is intentional (simple text editor), but I would have liked to see if behave like an IDE and increase the indentation for the highlighted lines.

Developer Response ,

Many thanks for the kind review, Rlatic; it is greatly appreciated.

Please highlight multiple lines then use the "Editor -> Shift Right (CMD+])" menu option, to indent multiple lines.

I sincerely hope that helps.

-- Mike.

Big Balagan ,

Does exactly what it does beautifully and clearly

If you want sequence diagrams this is the way to go. Not only can you devise all the basic flows, you do so with a interpreted “compiler” window that processes a set of simple commands/syntax. You might think this is round-about compared to directly manipulating graphical elements, but I find somewhat to my surprise that thinking about sequence construction using the app’s syntax is a much cleaner and more clear approach to design—and the drawing is done automatically and with pretty good aesthetic values too. This is a very unusual example of both perfect fit of execution to the problem space as well as providing enough, but not too much capability and without any missing. When you use a tool like this, the fit is so precise that tool use sort of disappears from your immediate consciousness and you just solve the problem. Tremendously productive, I learned in in about 15 minutes. Very very good work.

Developer Response ,

Thanks for the kind review, Big Balagan; it is greatly appreciated. -- Mike. 🤓

reidnez ,

Great Tool

This app does what I need, was easy to learn, and I've encountered no major bugs or stability issues. You 'write' your diagram in a very simple domain-specific language. Don't let that put you off, there's no real learning curve: it's very easy to copy and adapt from the excellent template provided. Your diagram is then rendered automatically as you go, and you can (of course) export as a PDF and such. It's a novel approach and I love it. If you're someone who appreciates the elegance and efficiency of text-based interfaces, you'll probably like it, too.

App Privacy

The developer, Mike O Abidakun, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy.

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The following data may be collected but it is not linked to your identity:

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  • Family Sharing

    With Family Sharing set up, up to six family members can use this app.