I don't have or want to learn Microsoft Visio or other complicated diagramming software.

Is there a web app to generate simple sequence diagrams?

  • genmymodel.com now supports sequence diagrams. – Xaelis Jul 30 '14 at 6:58
  • Could someone please explain why this is off topic? – Peng at ZenUML.com Dec 14 '18 at 3:12
  • @XiaoPeng-ZenUML.com according to the help center, recommendation requests are off-topic – Ooker Jan 22 '19 at 5:05

10 Answers 10


Gliffy Very easy to use. Look under "More Shapes" for loads of additional shapes you can add to the toolbar. Has various styles of connectors to link shapes. Lots of export options including .png .svg and own format.

  • I like this answer better than my own because it's more featureful. – Stephen Jennings Jul 12 '10 at 2:00

Web Sequence Diagrams lets you create sequence diagrams using a very simple scripting language. A simple script might look like this, with its results:

participant Client as C
participant Server as S

C->S: GET HTTP/1.0 /index.aspx
activate S
note over S: Generate HTML
S->C: 200 OK

HTTP Request

  • looks like online-graphviz :) – akira Jul 2 '10 at 5:13
  • 2
    I always forget about this tool when I need it, which is why I asked and answered my own question. The other answers here are welcome and useful, though. – Stephen Jennings Jul 2 '10 at 5:22
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    PlantUML is like WebSequenceDiagrams but supports additional diagram types. Diagrams may also be inserted inside Google documents. – Druvision Feb 12 '15 at 10:59

draw.io is a free online diagramming application capable of doing this. Currently you would have to group the two elements of the sequence object to get them to move together, but we'll improve that soon.

  • Because I got your answer to "review" under the peer reviewing system of this site and not the above answer. – user19533 Nov 29 '12 at 15:04
  • @David I can't find any template for sequence diagram at draw.io. Is there any or not? – Rocky Balboa Apr 4 '17 at 8:30

yUML is my personal favorite for generating diagrams, even if they're not necessarily UML.

  • So glad you posted this, awesome tool! – scunliffe Oct 19 '10 at 17:42

Google Docs -> Drawing


Cacoo allows collaboration.


I have created an online sequence drawer, with which you can draw a beautiful sequence diagram, with simple pseudo code. seqDia


Lovely Charts is very simple to use and has a web and desktop version.


Found another lightweight online sequence diagram tool: http://www.ckwnc.com/

It is similar to seqDia mentioned before. Transforms script to a diagram.

  • Per FAQ please disclose your affiliation with the mentioned site, otherwise this post could be deemed spam and removed as such. – Bradley A. Tetreault Oct 16 '12 at 14:52
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    My apologies. I am not related to this site not in any way. I googled "online sequence diagram" and it popped out as ~30th result. Before that I searched an answer from Stack environment and ended up here. Just found a lightweight tool that I wanted to share. – vellotis Oct 18 '12 at 7:18

If you're looking for a more intuitive program than Visio, LucidChart is a good option. It's a HTML5 application that you can pick up very quickly.

LucidChart has very robust UML tools to create sequence diagrams, state diagrams, activity diagrams, etc.

  • @Glorfindel That's really not an appropriate addition in my book. Please don't add someone's personal info without their permission. – jonsca Jan 21 '19 at 23:31
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    @jonsca I've answered the question on Meta why I feel these edits were necessary. – Glorfindel Jan 22 '19 at 7:57

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