To start with we should consider and think why we are comparing Angular and Flutter! When there are other technologies that we could compare. The answer is both the frameworks are developed by Google.
Angular is a hybrid framework which is good to build a web application as well as a mobile application but it gets complex when it comes to creating specific framework application for mobile.
If Angular is used to make a mobile application for android, then to build the same application for iOS, it should be rebuild from start.
To overcome this problem Google came with another framework called “Flutter” which is a single code-based language. Flutter is a framework and SDK that allows you to build native mobile apps for iOS and Android with one language.