Hate UML?

Draw sequence diagrams in seconds.

Tool for Creating UML Sequence Diagrams
Posted on: 2008-03-03 19:51:21

If you have to draw something called "UML Sequence Diagrams" for work or school, you already know that it can take hours to get a diagram to look right. Here's a web site that will save you some time:


You can just write the diagram out in text, click "Draw", and the web site will spit out an image. Then you can tell your boss that you slaved for hours in MS Visio perfecting every line...


Here's an example of what you'd write. Notice that the syntax is very natural.

Alice->Bob: Authentication Request
alt successful case
    Bob->Alice: Authentication Accepted
else some kind of failure
    Bob->Alice: Authentication Failure
    note right of Bob: Bob clears key cache  

... And here's the resulting image:

Hey, wait a minute...

Astute readers will notice that I am the author of websequencediagrams.com. Yesterday I added a note pleading with people to blog about it or at least link to it, and I figured that I should practice what I preach. So this article is nothing but a shameless plug for my other web site.

The fact is, the page doesn't have much text on it, so its hard for people to come across it by searching alone. I added it to Wikipedia and so far that's where most people find it. The more links I have, the more Googler's will find it.


Quick Sequence Diagram EditorJava program with confusing syntax.
mscgenUnix command line program. I was inspired by its syntax, but found it overly verbose.
Sequence Diagram EditorNice editor, if you love filling in text boxes. $99
TracemodelerA worthy competitor, though we have different views on the use of text. Its author, Yanic, and I try to see is first to mention our tool on web forums.

Want more programming tech talk?
Add to Circles on Google Plus
Subscribe to posts

Post comment

Real Name:
Your Email (Not displayed):

Text only. No HTML. If you write "http:" your message will be ignored.
Choose an edit password if you want to be able to edit or delete your comment later.
Editing Password (Optional):


2008-05-07 13:34:00
Your tool is excellent and I've been using it at work for last 2 weeks and really helped to debug some issues. I wrote a tool to generate the the text for your tool from our debug log. Then I copy the text into your tool to generate the sequence diagram to see whats going on. I'm working on wireless product and our debug log contains transactions exchanged by our wireless unit with remote base station.

Anyway, your tool is not working today. I click on Draw and nothing happens. Any ideas?

Didier Bretin

2008-05-09 08:36:57
Hi, do you plan to add another uml diagram ? Do you plan to

publish your sources ?


2008-07-30 02:55:45
Hi, your sequence diagram tool is excellent! Simple and easy to use. Thank you!

Steve Hanov

2008-09-14 16:05:29
I have rewritten the tool from scratch in C++ instead of python. This provides more reliability, so you should not experience any more outages. I found that python was rather flaky. The main reason is because the startup time was several seconds, so I had to run it as a server. If one diagram caused the tool to freeze somehow, then it was shot for the day. The new C++ code is fast enough to be started with each diagram request.

I plan to commercialize the tool. For the free version, you can generate all the sequence diagrams you want using the web interface, or even external tools using the HTTP interface. That should be sufficient for any open source or student projects. However, businesses can't use a tool where they have to post their confidential diagram on the web, so they will have to buy a copy to run locally.


2009-02-10 21:27:05
MS Visio has a nice set of 'UML' modeling templates, of which sequence diagrams is one of them. Visio is more than a drawing environment. It is exensible and for example, allows name exporting/matching to other objects, i.e. code module names, variable, etc.

This is not a plug for Visio, just an example of a tool that is often bundled with MS tool distributions on college campuses.

Kurt Avish

2009-04-12 01:17:26
You just catch my attention buddy! Wonderful tool. Gonna blog on this for you coz you just helped me save some hours of Visio lol. Thanks :-)




2009-04-15 09:58:42

your web based MSC tool is great! Hopefully you can launch the commercial version soon.




2010-03-12 08:11:34
uml sequence daigram of advertisement posting website

John Mathew

2011-02-09 06:46:13
I am using Visio 2010 for creating UML diagrams. It is a great diagramming software which simplifies the complexity with dynamic, data-driven visuals.


Marc Lepage

2011-03-26 18:17:34
The text to diagram principle is also evident in the classic programs Dotty and Graphviz.


2011-05-20 08:54:03
I just came across your tool while searching for easy to use sequence diagrams. I have to say, that it's perfect for my purpose. I always hated to fidle around with graphical tools. Here the tools takes care of the graphics itself. Perfect! Thanks a lot.


2011-08-26 04:09:31
Maybe an online diagramming app such as Creately could have been used here? Just a suggestion. :-)


2012-08-08 11:49:07
Came across your tool and found it very useful.

Other posts by Steve

Yes, You Absolutely Might Possibly Need an EIN to Sell Software to the US How Asana Breaks the Rules About Per-Seat Pricing 5 Ways PowToon Made Me Want to Buy Their Software How I run my business selling software to Americans 0, 1, Many, a Zillion Give your Commodore 64 new life with an SD card reader 20 lines of code that will beat A/B testing every time [comic] Appreciation of xkcd comics vs. technical ability VP trees: A data structure for finding stuff fast Why you should go to the Business of Software Conference Next Year Four ways of handling asynchronous operations in node.js Type-checked CoffeeScript with jzbuild Zero load time file formats Finding the top K items in a list efficiently An instant rhyming dictionary for any web site Succinct Data Structures: Cramming 80,000 words into a Javascript file. Throw away the keys: Easy, Minimal Perfect Hashing Why don't web browsers do this? Fun with Colour Difference Compressing dictionaries with a DAWG Fast and Easy Levenshtein distance using a Trie The Curious Complexity of Being Turned On Cross-domain communication the HTML5 way Five essential steps to prepare for your next programming interview Minimal usable Ubuntu with one command Finding awesome developers in programming interviews Compress your JSON with automatic type extraction JZBUILD - An Easy Javascript Build System Pssst! Want to stream your videos to your iPod? "This is stupid. Your program doesn't work," my wife told me The simple and obvious way to walk through a graph Asking users for steps to reproduce bugs, and other dumb ideas Creating portable binaries on Linux Bending over: How to sell your software to large companies Regular Expression Matching can be Ugly and Slow C++: A language for next generation web apps qb.js: An implementation of QBASIC in Javascript Zwibbler: A simple drawing program using Javascript and Canvas You don't need a project/solution to use the VC++ debugger Boring Date (comic) barcamp (comic) How IE <canvas> tag emulation works I didn't know you could mix and match (comic) Sign here (comic) It's a dirty job... (comic) The PenIsland Problem: Text-to-speech for domain names Pitching to VCs #2 (comic) Building a better rhyming dictionary Does Android team with eccentric geeks? (comic) Comment spam defeated at last Pitching to VCs (comic) How QBASIC almost got me killed Blame the extensions (comic) How to run a linux based home web server Microsoft's generosity knows no end for a year (comic) Using the Acer Aspire One as a web server When programmers design web sites (comic) Finding great ideas for your startup Game Theory, Salary Negotiation, and Programmers Coding tips they don't teach you in school When a reporter mangles your elevator pitch Test Driven Development without Tears Drawing Graphs with Physics Free up disk space in Ubuntu Keeping Abreast of Pornographic Research in Computer Science Exploiting perceptual colour difference for edge detection Experiment: Deleting a post from the Internet Is 2009 the year of Linux malware? Email Etiquette How a programmer reads your resume (comic) How wide should you make your web page? Usability Nightmare: Xfce Settings Manager cairo blur image surface Automatically remove wordiness from your writing Why Perforce is more scalable than Git Optimizing Ubuntu to run from a USB key or SD card UMA Questions Answered Make Windows XP look like Ubuntu, with Spinning Cube Effect See sound without drugs Standby Preventer Stock Picking using Python Spoke.com scam Stackoverflow.com Copy a cairo surface to the windows clipboard Simulating freehand drawing with Cairo Free, Raw Stock Data Installing Ubuntu on the Via Artigo Why are all my lines fuzzy in cairo? A simple command line calculator Tool for Creating UML Sequence Diagrams Exploring sound with Wavelets UMA and free long distance UMA's dirty secrets Installing the Latest Debian on an Ancient Laptop Dissecting Adsense HTML/ Javascript/ CSS Pretty Printer Web Comic Aggregator Experiments in making money online How much cash do celebrities make? Draw waveforms and hear them Cell Phones on Airplanes Detecting C++ memory leaks What does your phone number spell? A Rhyming Engine Rules for Effective C++ Cell Phone Secrets