When comparing Proto vs Principle, the Slant community recommends Proto for most people. In the question“What are the best tools for prototyping mobile interactions/animations?” Proto is ranked 9th while Principle is ranked 12th. The most important reason people chose Proto is:
Ranked in these QuestionsQuestion Ranking
Pro It allows you to use JSON animations (such as Lottie)
Pro Has one of the largest gestural support libraries in the market
Proto supports one of the (if not the) largest gestural support libraries out of all the prototyping tools. With gestures such as:
- Double tap
Pro Native prototype testing
Developers can build prototypes through the browser with Proto, but the testing itself is done on the devices. Proto has released native apps for both iOS and Android that developers to test their designs right on the native device itself.
Pro Easy to use with it's intuitive drag-and-drop interface
Proto is very easy to use even for beginners, or programmers who are not well-versed in Photoshop or Sketch or any other drawing application. With it's easy drag-and-drop interface and with a wide library of commonly used UI elements for Android and iOS, prototyping with Proto is very simple.
Pro Design and prototype all in one tool
Better UX to not switch between multiple tools.
Pro Preview prototypes on the device (e.g. iPhone, Android phone)
Pro User testing / screen recording capabilities
Pro Comprehensive help & examples
You can find videos for the Principle app course here.
Pro Simple Sketch import
Import Sketch layers easily to animate your designs.
Pro Build iOS transitions & animations easily
All the iOS easing info is built-in.
Con The mobile app for previews doesn't look as good as the preview on the browser
That can be very disappointing. Once you have everything perfect the design becomes different when you open it on your mobile app.
Con Since it opens on browser, it can get very laggy
Once you start using lots of images, vectors and animations you can go into deep trouble.
Con Only a free trial
Other prototyping tools offer free plans to trial as long as one wants, but Proto only offers a trial that while has full functionality has a 15 day time limit.
Con Prototyping can be relatively slow
Proto's animations and interactions are very detailed. As far as prototyping goes Proto is probably the best tool to get as close to the actual app as possible. But this brings the downside that prototyping with Proto becomes quite slow and can take several hours to finish to get everything to work perfectly.
Con Mac only
Sadly iOS centric.