When comparing Diagrams.net vs Axure, the Slant community recommends Diagrams.net for most people. In the question“What are the best mockup and wireframing tools for websites?” Diagrams.net is ranked 6th while Axure is ranked 15th.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Rich functionality for a web-based application
Pro Integrates with multiple cloud storage services
Draw.io offers saving files directly to services such as Google Drive, OneDrive or Dropbox along with saving to to computer.
Pro Real-time collaboration
Pro Great flexibility customizing text labels
Pro Completely free
Pro There is also a Desktop version
Pro Good list of different output formats
Draw.io supports export for PNG, GIF, JPEG, PDF, SVG, HTML, and XML.
Pro Internet Explorer 6-8 and touch device support
Draw.io works with every browser (even IE 6) without plugins.
Pro Supports web and mobile prototyping
Allows creation of interactive HTML mock-ups which is accessible for both websites and mobile applications.
Pro Lots of options for sharing your work
Great web options, but you can also save your wire frames out to Word and convert the notes to annotations.
Pro Resuable components
You can create a component (widget) that you can use over and over again.
Pro Cross-platform
Available for use on Windows and Mac.
Pro Collaboration tools
You can set up a project with SVN-like check-in/out system to work with others.
Pro Offers resources to help you get proficient with the software
There is a wealth of online training including videos for getting the basics down, a great community to mine, and support team to help assist with more technical details.
Cons
Con Import from Visio .vsd is useless
Even simple diagrams get all scattered.
Con Behaves strangely for certain diagram types
For example the snapping function for arrows doesn't work properly for the sequence diagram template.
Con Moderate learning curve
Con Expensive [$289-$589]
There is a free trial to work with Axure, but there is a hefty price for the standard edition at $289. Even more so, the Pro edition will cost $589.