UML stands for Unified Modeling Language, which is used in object-oriented software engineering. Feel free to check out for the following top 3 best free online UML diagram editors to create your UML diagrams freely and effortlessly.
Cacoo is the easiest online UML diagram tool with hundreds of UML templates and stencils. You can get started quickly with one of the designs, or customize it on your own. It also supports working simultaneously with your team members to collaborate ideas. You can even send a completed file as in an URL link.
- Platform: Web-based
- UML diagrams types supported: Case diagrams, Sequence diagrams, Class diagrams, Activity diagrams, Package diagrams, etc.
- Unique feature: A Built-in Cloud service to let you access files anywhere – no downloads necessary.
GenMyModel is another free and awesome tool to create UML diagrams, flowcharts online with ease. It generates documentation PDFs on entire diagrams and on each element and exports your models in SVG, PNG, JPEG. Google Drive-style collaboration function navigates in your online centralized model repository, shares your projects with your team workers, edits your UML diagrams in real-time.
- Platform: Web-based
- UML diagrams types supported: class diagrams, activity diagrams, use case diagrams, object diagrams, sequence diagrams.
- Unique feature: it saves major and minor versions of your models to identify which ones you want to deliver. Conserve modifications history.
Grapholite is an easy to use, touch-friendly, yet a very powerful UML diagram making tool that can be also used for creating flowcharts, floor plans, office layouts, organizational charts, mind maps, Venn charts and more. An intellectual algorithm of connector layout helps you make automatic connections between the diagram elements as neatly as possible. You are able to export your work as the high-resolution bitmap (png, jpeg), pdf, Visio (VDX) or a vector drawing (SVG).
- Platform: Web-based, Android, iPad
- UML diagrams types supported: class diagram, component diagram, object diagram, package diagram, composite structure diagram, deployment diagram, activity, use case diagram, sequence diagram, etc.
- Unique feature: the ability to work in online and offline modes; in and out of the browser.
It is not hard to find there are unique features on each of those 3 UML diagram tool online. Hopefully, you can choose your favorite one and get started.