Flutter vs. React Native: Mobile App Dev Framework Comparison for 2021

Reading Time: 5 minutes

Cross-platform native mobile app development has been around for many years now with early players like NativeScript and Titanium and Xamarin and newer players like Flutter and React Native.

However, the market is now more or less settled. Except Xamarin, which specifically caters to .NET developers, the two contenders are React Native and Flutter. So you may be searching what is the difference between React Native and Flutter and which cross-platform native app development framework you should be using or you may be asking what I should use for mobile development.

In this article we will talk about differences and similarities between Flutter and React Native in the 2021 landscape.


Table of Contents


What is React Native and what is Flutter?

About React Native

React Native is an open-source mobile app framework created by Facebook. React Native app development is done with JavaScript and you can develop native iOS and Android apps with React Native.


About Flutter

Flutter framework is an open-source user interface toolkit created by Google. However, Flutter has a great community and, it is way beyond the “Google Flutter” nomenclature. Flutter app development is done with the Dart language and you can develop iOS, Android, and web apps with Flutter.


How do the community and the popularity of Flutter and React Native compare?

React Native has been around longer than Flutter, but based on Google Trends, React Native is showing a steady decrease in popularity while Flutter is showing a steady increase.

The same goes for the number of stars on GitHub. Flutter has 124k stars while React Native has 97k stars as of July 2021.

Even though Flutter is more popular than React Native as of 2021, both Flutter and React Native have large and active communities.


Which programming language is better? Dart for Flutter or JavaScript for React Native?

Flutter uses the Dart language, which is actually a very recent language created by Google. It is an object-oriented language and easy to learn for developers from different backgrounds.

React Native uses JavaScript, which is widely used by web developers and by may other developers. The large adoption of JavaScript compared to Dart makes it a preferable choice, though for beginners, Dart is a “safer” language compared to JavaScript.


How does code sharing work for Flutter and React Native for cross-platform output?

Code sharing is significantly different for React Native and Flutter. React Native is not single codebase and only a certain amount of code can be shared across iOS and Android projects. Flutter is single codebase and you can use the same code to deploy iOS and Android apps (plus the other target platforms).


How is productivity compared for Flutter and React Native?

The difference between code sharing has an important impact in developer productivity difference between Flutter and React Native. If you are targeting a single platform, this does not matter, but if you are targeting multiple platforms, having a single codebase will increase the productivity. (Not as much as 100% though since every target platform has its unique cases.)


What are the architectural differences between Flutter and React Native?

The architecture difference between React Native and Flutter mainly lies on the nature of the languages. JavaScript is interpreted during runtime and converted to native code via a bridge while Dart is compiled to native code directly. For this reason, React Native apps are more flexible with more options for modularity and on-the-fly app updates, however Flutter is better optimized without an additional bridge layer.


Which one has better performance? Flutter or React Native?

Based on the architectural differences, if you ask what to choose for performance of Flutter vs. React Native, the preference depends on the use case. If your app is graphics-heavy, Flutter may provide better peformance, but if you need higher flexibility, you may find the performance difference between React Native and Flutter negligible.


How is CI/CD handled for Flutter vs. React Native?

The release processes for any kind of mobile app is more or less dictated by Apple and Google and even though Flutter and React Native have their own way building apps, eventually, you will need to generate an Android and an iOS binary for your app.

For both platforms, you can use Appcircle as a mobile CI/CD tool to automate build, testing and deployment processes both for Flutter and for React Native apps. For this reason, if you use a mobile-specialized tool like Appcircle, you don’t need to worry about differences in Flutter and React Native build flows.

Using Appcircle, you can build and deploy Flutter and React Native apps to the App Store without the need for a Mac.

Automated Mobile CI/CD for Flutter and React Native


Which one is more stable, Flutter vs React Native Stability?

A few years back, we could have said that both Flutter and React Native has stability issues, but as of 2021, they are relatively stable, though React Native still hasn’t achieved version 1.0 up until now. There may be still issues here and there or there may be new cases as Android 12, Android 13 and iOS 15, iOS 16 are released, but otherwise Flutter and React Native are sufficiently stable.


What are the UI differences between Flutter vs React Native?

One of the major differences between Flutter and React Native is how they approach to user interface generation. React Native utilizes the actual native components and generate an actual native UI. This has the advantage of having an up to date interface as the OS versions change, but this also has the risk of incompatibility if there is a change in the operating system APIs.

Flutter, on the other hand, has its own UI components. These are not the actual OS components, but they are also native and does not cause any performance issues. (Consider how games use their own interface independent from the OS.) This has the advantage of having a more stable and consistent experience across platforms, but this can also be considered as a disadvantage if you want to differentiate the experience across platforms, where you will need to use different UI kits for different target operating systems.

Flutter vs. React Native Summary and Verdict

Talking about the Flutter and React Native comparison, it is not really possible to determine a certain winner. For choosing between React Native and Flutter, there are so many factors to consider, so your decision will depend on your use case. What kind of a mobile app you will develop, which technologies will you use, which platforms will you target and so on.


All in all, it’s a complex world for React Native and Flutter and at least you don’t need to worry about which tool to select from a CI/CD perspective.

Appcircle simplifies and automates pipelines for Flutter and React Native so that you can build, deploy, and test your mobile apps easily and quickly. Appcircle supports iOS and Android app builds within your React Native or Flutter pipelines along with Flutter web.


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