Let’s talk sequence diagram tools. What are they? What can you use them for? Which one is best for you and your team? We’ve compiled a list of the top 8 UML sequence diagram tools on the market in 2021, and can hopefully answer some of these questions for you.

Sequence diagrams are just one of several types of UML diagrams that software developers and other professionals use to make their projects come to life. Check out our post on everything you need to know about UML diagrams to learn more.

What is a sequence diagram?

Sequence diagrams, also known as ‘event diagrams’, show how different parts of a system interact with each other over time. Basically, sequence diagrams track the messages sent between components of a system. As you might guess, they express these events in the order of which they occur, in other words, in a sequence.

Make your own UML sequence diagram with Gleek.

When to use a sequence diagram

So when should you use a sequence diagram? There are several scenarios that are best expressed through this type of visual aid.

  • See system functionality – Developers can easily see what functions each object performs and when.

  • Predict object behavior – When designing systems, developers use sequence diagrams to predict how the objects will behave.

  • Future system implementation – When updating a preexisting system, a sequence diagram is used, then refined, by analysts to see what is required in order to successfully update a system, or to implement a new one.

Top 8 UML sequence diagram tools

Sequence diagram tools are used by software developers and professionals in other industries to map out systems in a way that’s easy to read and change.



Lucidchart is one of the highest-rated diagramming tools currently on the market. They offer a wide variety of diagram templates, a full shapes library, and impressive collaboration features. To get a more in-depth look at what this app can do, check out our side-by-side comparison of Lucidchart with Gliffy. Here are some other features that might attract you to Lucidchart.

  • Free version

  • Several tiers of paid versions

  • Online and mobile apps

  • Drag and drop creation

  • Remote collaboration

  • Presentation tools

  • Progress tracking



Gleek is quite different when compared to the other tools on this list. Rather than using a drag and drop system like Gliffy or Lucidchart, Gleek is entirely text-based. So instead of scouring through a library of images, you simply type commands into the text box to create your diagram. Hate downloading programs? No problem. Gleek is an online tool that lets you start right away.

Read more on how to create a sequence diagram using Gleek on Library management system example.

  • Free version

  • Start creating immediately

  • Basic, sequence, entity relationship, and class diagrams

  • Online tool – no download

  • App plugin for Confluence

  • Video tutorials

  • Link sharing



Another main competitor in the UML diagram market is Gliffy. This is a simpler program for the more artistic or inexperienced diagrammers who like flexibility and diverse options. Gliffy is highly compatible with other programs, including Confluence and Jira. Importing and exporting diagrams is a breeze, and their shapes library has everything you need to create your diagram.

  • Free trial

  • Paid options

  • Drag and drop creation

  • Import old diagrams

  • Remote collaboration

  • Diagram templates

  • Sharing and publishing capabilities



For those among us who are less tech-savvy, or who are new to making UML diagrams, Draw.io offers an easy to use drag and drop program. It lacks the collaboration features of Lucidchart and Gliffy, but users can share files using Google Drive. A more detailed breakdown of what Draw.io can do can be found in our recent post Lucidchart vs Draw.io.

  • 30 day free trial

  • Paid versions, best for teams

  • Online app

  • Start immediately

  • Some diagram templates

  • Full and custom shapes library

Visual Paradigm


If you’re an experienced diagrammer with a large or small team setting, Visual Paradigm will be a great fit for your team. Not only can you create diagrams, there are a lot of other tools for project management, such as quality improvement tracking, scrum processes, and enterprise architecture tools. Visual Paradigm is more than just a diagram tool, which makes it an attractive fit for large enterprises.

  • 30 day free trial

  • Subscription or perpetual options

  • Downloadable program

  • Written tutorials

  • Agile and sprint management tools

  • 200+ diagram types

  • Massive shapes and photos library

  • Click and drag interactions

Star UML


Star UML is geared towards developers using agile and concise modelling methods. As such, the types of diagrams you can create are limited to those found within the software development field, like class diagrams and entity-relationship diagrams. It’s functional across multiple platforms, including MacOS, Windows, and Linux. Star UML is focused on functionality and efficiency, with no bells and whistles.

  • One time purchase

  • Downloadable program

  • Supports code generation

  • HTML document export

  • Information library

  • Open APIs

Make your own UML sequence diagram with Gleek.



Creately is a fun, colorful tool that can be used by teams in all types of industries, such as education, marketing, IT, and manufacturing. Their diagram templates are sorted by profession, which makes the diagram type you need easy to find. Creately is very user-friendly, so even beginners can get into the swing of things quickly.

  • Free version

  • Paid versions for personal use, teams, and enterprises

  • Online app

  • Drag and drop

  • Real time team collaboration

  • Video chat capabilities

  • Many styles and templates

  • Smart shapes and shape library

UML Designer


Last but not least on our list is UML Designer. This is an open-source program for software developers. Meaning, that if you’re looking for something that can be used by everyone in your team, this may not be the program for you. UML Designer offers a lot of support in the form of tutorials and guides, and they often release update bundles.

  • Free downloads

  • Downloads for MacOS, Windows, and Linux

  • Menu-based creation

  • Tutorials and guides

  • Diagrams for UML 2.5 models

  • Based on Sirius

Now that you’ve got a list of some of the best sequence diagrams tools on the market, it’s time to go out and create! Interested in trying the text-based app, Gleek? Click here to get started for free.

Related posts

10 Best data modeling tools: Free & Open Source

Top 12 Lucidchart alternatives in 2022

10 Best & useful software development tools in 2022

11 Best ER diagram tools to use in 2022

9 best Confluence plugins and add-ons in 2022

Best 7 UML tools to use in 2022