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 in Diagram Text Editor
• Error highlighting
• Canvas zoom up to 14x
• Collapsable Diagram 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 1.6.1

* Adds support for command line exporting (see Help/Sequence Diagram Help)
* Fixes a crash when modifying an empty document.
* Fixes a defect where Participant Boxes would have the wrong label text colour in exports
* Fixes defect where auto-signal numbers would be excluded from exports
* Fixes an SVG export defect where Interaction Frame guard clauses would have the wrong text colour
* Adds drag and drop support to application window.
* Now exports using default diagram colours (unless intentionally overridden in the document)
* Fixes a defect where syntax colouring could be lost, in large documents
* Improves support for observing changes to the file, when edited externally
* Improves support for CJK(V) character sets

Other recent enhancements
* Fixes a defect where interaction frames could be widened in exports
* Default save location is now the same as the source file's location
* Minor performance improvements when working with large documents
* Now remembers Auto-Complete, Auto-Signal Numbering and Line Number preferences
* Improves element grouping in SVG export
* Adds support for dragging the Diagram Canvas

A massive thank-you for all the feedback and suggestions.

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

Thanks again for your valued support.

-- Mike

Ratings and Reviews

4.9 out of 5
19 Ratings

19 Ratings

sfyire ,

Nice additional to my workflow

My only nit pick would be the viewport for writing in the sequence diagram, it's all or nothing, when lines start wrapping around it can get a bit hard to read

Being able to have a handle that would let me control the size of the viewport for the left window would be a nice addition

Spartan Slasher ,

Easy to use app

Needed to create some sequence diagrams quickly, this app was perfect, tried to use a dev environment before hand, cumbersome and slow to get running with plugins. This app worked a treat for what i needed. Would love to have a larger font options output for Jpegs and PDFs though, but otherwise spot on.

teo2k ,

Great app!

I’ve been looking for something simple that won’t need me to drag stuff around and this is perfect!

An improvement could be adding a feature to allow for choosing the background color on the exports

Developer Response ,

Thanks for the kind review, teo2k; it’s greatly appreciated.
Check out the latest release, which includes the ability to choose to use your custom colours or the default colours, when exporting to SVG.

— Mike. 🤓


Mike O Abidakun
11.2 MB

OS X 10.11 or later, 64-bit processor



Age Rating
Rated 4+
© Mike O. Abidakun


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