When comparing Ionic Framework vs Flutter, the Slant community recommends Flutter for most people. In the question“What are the best frameworks for developing cross-platform mobile apps?” Flutter is ranked 1st while Ionic Framework is ranked 4th.
Ranked in these QuestionsQuestion Ranking
Pro Cordova plugins
Large quantity of plugins to access native APIs without code nothing in native language.
Pro Large, friendly and active community
Ionic Framework is currently one of the most popular frameworks for hybrid mobile app development. This has resulted in a very large community of active users who contribute to the community by writing tutorials and answering questions.
Pro Free and open source
Ionic is free to use and open source, resulting in an active and helpful community of users and contributors.
Pro Great developer tools debug/hotreload/analyser
Pro Based on Dart language
Dart is a Java like language, easy to learn and startup fast for millions of Java developers.
Pro Open source
Pro A single codebase for iOS AND Android
The developer's goal is to allow people to make apps running at 120 FPS.
Con Still in development
According to the website, Flutter is still in its early stages of development.
Con Dart is unpopular and never gained serious community traction like Kotlin or Java
Con Does not support 32-bit iOS devices
If you plan on targeting iPhone 5, 5C or earlier, you can forget about Flutter.