Many times we need to draw a UML diagram and don’t know how to start. But things get easier when you use online UML diagramming tool for this purpose.
There is a shortage of quality UML tools and open source UML diagram tools which allow you to create professional looking UML diagrams for free. However, If you are planning to use UML diagrams in development, this article will help you with some great alternatives.
Diagrams.net
Diagrams.net (formerly draw.io) offers a simple drag-and-drop interface for flowcharts and graphs, but also works for UML as well. Diagrams.net works well for a wide variety of tasks, but may not have enough specialized functions for some users. If you seek a drag-and-drop UML solution, draw.io costs a bit less than Lucidchart and offers the same ease-of-use for general users.
Input type:
- Drag-and-drop
UML diagram types that diagrams.net specializes in:
- Case diagrams
- Sequence diagrams
- Activity diagrams
Cacoo
Cacoo gives a great diagramming experience to a wide variety of users. Most people will be able to start diagramming very quickly with Cacoo’s intuitive drag-and-drop interface. Cacoo also offers real-time collaboration, so teams can find problems together quickly. You do not need to know everything about UML to use Cacoo. Cacoo might not meet the needs of every developer. It’s a drag-and-drop solution aimed at a general audience of users.
Input type:
- Drag-and-drop
UML diagram types that Cacoo does well:
- Use case diagrams
- Sequence diagrams
- Activity diagrams
Microsoft Visio: the UML drawing tool for Office users
Microsoft Visio is a popular chart and visualization software and belongs to the Office family. Therefore, Visio can be easily integrated into the suite. For example, if you use Office Pro 365, Microsoft offers you a subscription extension for Visio. However, the cost will be added to your Office subscription. Visio Online Plan 2 includes a desktop app and a web-based editor for up to five PCs (volume licensing on request).
Alternatively, you can get Visio Professional as a permanent license at a steep premium. This version includes a desktop app, the browser applications, and an iPad app. Visio Standard does not support UML diagrams and is therefore not included here. As UML tools, the Visio versions presented are primarily aimed at corporate customers who appreciate the familiar Office environment and want to optimize their workflow by seamlessly integrating the appropriate modeling tool into their existing system.
If you need a comprehensive shape library with current UML notations standards and if you have already subscribed to Microsoft Office Pro 365, we recommend Online Plan 2. Note
A desktop Visio version for Mac is currently not available. The previously mentioned cloud-based app, Lucidchart, can serve as a mediator since it also imports native formats from Visio.
Visio is largely limited to features that allow you to draw industry-standard vector graphics and diagrams and work in a team. If you release a diagram, authorized team members can work on it simultaneously in the document as well as exchange ideas. Visio can also be integrated with Microsoft Teams to make collaboration easier. You simply share finished sketches and prototypes via the connected cloud.
If you want to create code frames from your diagrams, you need other UML tools, for example, Visual Studio from Microsoft. As this is also part of the product family, the integrated development environment allows Visio to be integrated into the development process. Save your work in the UML diagram tool in native OPC/XML metadata formats so that you can export your diagrams and continue working on them without any data loss.
Native Visio formats:
- VSD (drawing)
- VSS (stencil)
- VST (template)
- VSW (web drawing)
- VSDX (OPC/XML drawing)
- VSDM (OPC/XML drawing, macro-enabled)
- VSSX (OPC/XML stencil)
- VSSM (OPC/XML stencil, macro-enabled)
- VSTX (OPC/XML template)
- VSTM (OPC/XML template, macro-enabled)
- VSL (add-on)
Visio has neither code generation nor round-trip engineering functions. However, it enables reverse engineering where you create UML diagrams from imported data or source code. Therefore, the UML tool fulfils its main task, which consists of clearly displaying processes and systems. Visio also enables you to integrate real-time data into your diagrams with a single click. This so-called data linking illustrates complex business processes (with BPMN) during their entire runtime, for example. Alternatively, you can test dependencies within a system using a UML communication diagram – live with real data.
| Advantages | Disadvantages |
|---|---|
| ✔ Supports UML 2.0 (Online Plan 2 also supports UML 2.5), including XML metadata | ✘ Steep learning curve for beginners |
| ✔ Real-time data linking helps with live testing | ✘ Expensive compared to other options |
| ✔ Clear user interface with familiar ribbon menu | ✘ No integrated code frame generation |
StarUML
StarUML is an open-source software modeling tool, which is provided by MKLab. It has come up with eleven different types of modeling diagrams. It also supports UML2.0 specified diagrams.
Features:
- It let you create Object, Use case, Deployment, Sequence, Collaboration, Activity, and Profile diagrams.
- It is a UML 2.x standard compliant.
- It offers multiplatform support (MacOS, Windows, and Linux).
Download link: http://staruml.io
Umbrello
Umbrello is a Unified Modeling language tool, which is based on KDE technology. It supports both reverse engineering and code generation for C++ and Java.
Features:
- It implements both structural and behavioral diagrams.
- It imports C++ and can export up to a wider range of languages.
Download link: https://umbrello.kde.org
UML designer tool
The UML designer tool helps in modifying and envisioning UML2.5 models. It allows you to create all of the UML diagrams.
Features:
- It provides transparency to work on DSL as well as UML models.
- With the UML designer tool, the user can reuse the provided presentations.
- It implements Component, Class, and Composite structure diagrams.
- To start working with DSL, you can use UML legacy models.
Download link: http://www.umldesigner.org/download/
Altova
Altova has provided UModel, which is another UML software modeling tool. It supports all types of 14 UML2 diagrams as well as SysML for the embedded systems. It also holds up for business process modeling for enterprise analysts. It generates visually designed software models by incorporating Java, C++, and C #or Visual Basic .NET.
Features:
- It provides a dedicated toolbar for an individual diagram.
- It offers unlimited undo/redo, which inspires to discover new ideas.
- In UML diagrams, you can easily add a hyperlink to any element.
- It also provides an intuitive color-coding, icons, customized alignment grid, and cascading styles for colors, fonts line size.
Download link: https://www.altova.com/umodel
Umple
Umple is an object-oriented and modeling language that textually supports state diagrams and class diagrams. It adapts JAVA, C++, and PHP, which results in more readable and short lines of code.
Features:
- It includes Singleton pattern, keys, immutability, mixins, and aspect-oriented code injection, which makes UML more understandable to the users.
- It enforces referential integrity by supporting UML multiplicity.
Download link: https://cruise.eecs.uottawa.ca/umple/
Visual Paradigm
A visual Paradigm is a tool that supports SysML, UML2, and Business Process Modeling Notation from Object Management Group. It involves report generation as well as code generation.
Features:
- It supports all of the 14 UML2 diagrams.
- It supports BPMN 2.0, ERD, ORMD, SysML.
Download link: https://www.visual-paradigm.com
WhitestarUML
Whitestar UML is a division of StarUML 5.0 that offers bug fixes and has improved its compatibility with the latest operating systems, i.e., support of Unicode strings or simply being developed and tested on Windows 7 and 8.
Features:
- It offers a refreshed user interface.
- It completely handles the functioning of Unicode strings.
- It provides support on Windows 7, 8, and 10.
- On-demand upload and download of units.
- It directly integrates the ERD profile and extends to generate and parse the SQL tables.
Download link: http://whitestaruml.sourceforge.net
Gliffy: an online UML tool for beginners
The online application Gliffy is a cloud-based UML tool for the browser. First released in 2006, the modeling tool creates all types of diagrams such as flowcharts, Venn diagrams, and of course, UML diagrams. The online tool was written in HTML5 and scores points with its fast reaction time. Even before Gliffy went through the beta phase in 2007, the company (under the same name) cooperated with the Australian software group Atlassian. As early on as 2006, its collaboration software, Confluence, integrated a Gliffy plugin. Later, the Gliffy team developed a plugin for Jira. Google’s Workspace and Drive also contain the UML tool.
Whether as a plugin or standalone browser version, the software is ideal for teamwork. You can share read-only versions as well as actively work on diagrams simultaneously and exchange information using the integrated comment function.
Before you can use Gliffy, sign in with your email address or a Google, Microsoft, or Facebook account. After the free trial period of 14 days, it can only continue to be used for free with limited functionality. However, you can upgrade to a premium account with a monthly subscription.
Gliffy has a large, well-assorted shape library. In addition to UML, you can use it to model simple flowcharts or business process modeling and notations (BPMN), among other things. At the beginning, an orientation window allows you to define your desired modeling language. If you select groups, the corresponding tools are highlighted in the menu bar. Grid and guidelines allow you to place diagram elements precisely where you want them.
The theme tool should determine the color family for the diagram but is limited to the arrow elements in the test. By clicking on classes, components, and the like, you can still quickly adjust the color and font of the symbols. You can also create different layers in no time by clicking on the corresponding menu item (far right in the tool bar). In addition, you do not have to plan the diagram construction step by step in advance. You can simply undo errors with the delete function. If you want to insert an element, Gliffy detects the change and suggests appropriate insert options.
As a free UML tool, Gliffy imports diagrams in GON, Gliffy, and gXML formats. For the Microsoft Visio format, VDX, you need a business account. The same applies when exporting common image formats such as JPG, PNG, and SVG and the connection to Google Drive. Free accounts also have the native “Gliffy” format. Save a document in this format, share it easily with others via a download link, or embed it on various platforms such as HipChat, Slack, Confluence, or WordPress.
A free account also provides 2 MB of cloud space for your diagrams and allows you to share five models publicly at the same time. With a paid account from about $7.99 per month, Gliffy offers you even more possibilities: unlimited memory, diagram import from Visio, and export to the mentioned image formats. An enterprise account is required for significantly more performance. For such high demands, however, there is better software.
| Advantages | Disadvantages |
|---|---|
| ✔ Suitable for all current browsers | ✘ Features such as image export and Google Drive interface can only be used in group business |
| ✔ Extensive support | ✘ No debugger |
| ✔ Integrated team communication | ✘ Does not create code |
| ✔ Fast operation thanks to HTML5, drag-and-drop, and clear user interface | |
| ✔ UML 2 compatible |
Conclusion
A UML (Unified Modeling Language) diagram is a graphical representation that can be used to describe the structure of a system or design. A UML diagram can describe a variety of systems including networks, business processes, computer programs and even your website. There are a number of different types of UML diagrams, each with their own purpose and function.