When comparing Diagrams.net vs ProtoPie, 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 ProtoPie is ranked 20th.
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 Smooth and gradual learning curve
As the interface is very clean and simple, it enables you to create interactions by combining objects, triggers and responses just like that. No need for wireframing or shitty mockups, just get to hi-fi prototyping right away.
Pro Native prototyping
Deploy prototypes on any device right away. What's the point of prototyping mobile apps if you cannot deploy it on your mobile devices easily?
Pro IoT, Interactions across devices
Create prototypes e.g. chat platforms, payment apps etc. and deploy them on multiple devices and have them communicate with each other.
Pro Utilizes sensors very easily
Easily control the sensors of smart devices in your prototype, such as tilt, sound, compass, proximity sensor, vibration motor and 3D Touch sensors.
Pro Runs on Mac and Windows
It offers the same features on both MacOS and Windows. Plus, you can switch machines as long as you are logged in to ProtoPie Studio.
Pro Fast and easy sharing
Sharing is very easy via the cloud. Open the prototype in desktop or mobile browser, or deploy the prototype on the ProtoPie Player app. All is possible.
Pro Code Free
No coding needed to do interactions for your prototypes. You just choose the objects and link them with the triggers and responses you want to based on your preferred interactions.
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.