When comparing Onsen UI vs NativeScript, the Slant community recommends NativeScript for most people. In the question“What are the best frameworks for developing cross-platform mobile apps?” NativeScript is ranked 9th while Onsen UI is ranked 11th. The most important reason people chose NativeScript is:
Used by Svelte framework for native development.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Open source and free
Onsen UI is open source, and completely free to use.
Pro Can be used for web apps as well
Onsen UI is usable for classic web development as well as mobile.
Pro Large selection of components
Onsen UI provides a wide selection of components that are ready to use out of the box and are easily customizable.
Pro Easy to use
Onsen UI provides very clear, well-written and detailed documentation.
It uses popular technologies that are likely already familiar to developers (such as jQuery and Angular).
The framework is semantic and intuitive to use, making it quite fast to learn.
Pro Supports React
React is the most trending front-end UI framework, naturally supporting that is a plus.
Pro Svelte Native
Used by Svelte framework for native development.
Pro Leverages knowledge in Angular
Angular is a very popular framework, and teams already developing angular will feel right at home with Nativescript + Angular
Pro Works great with vue.js
Cons
Con Nativescript + Angular apps for Android tend to have long startup times.
It's very difficult to have acceptable startup times with NS+Angular in Android. It's not uncommon to see apps taking 6 sec or more to start AFTER having been optimized with Webpack (mandatory!). The same app in iOS takes only 2-3 sec. Also, this seems to happen only with the NS+Angular flavour. People using plain NS (without Angular) don't seem to have the issue.