Sometimes, mobile development can feel a lot like rolling the dice. Every agency tells you something different, this is because there are plenty of viable options and agencies will suggest what they are more familiar with.
With languages like Swift or Objective-C for iOS development, and Java or Kotlin for Android development, there’s definitively no shortage of languages, frameworks, libraries, or tools out there, and it can be difficult to know what’s right for your project.
If cross-platform development is on the cards, then it’s tempting to go all in on what many development teams consider the safe bet: React Native.
However, the smart money might just be on Google’s frontend framework, Flutter.
Launched in 2015, React Native has a lot going for it. Boasting a truly staggering developer ecosystem, React Native is widely considered the de facto standard when it comes to cross-platform app development. It’s certainly easy to see why, especially in the United States, where Google Trends data shows that React Native and Flutter remain locked in a near-perfect tie, with search interest essentially overlapping since early 2021. (Google Trends — US)
Backed by Meta, React Native powers apps that you’ve almost certainly used today. Facebook, Instagram, Discord, Coinbase and UberEATS, to name just a few are all built with React Native. Coupled with the fact that your development team probably already know JavaScript and React, React Native has a seemingly unassailable position as king of the cross-platform mountain.
Written in JavaScript, or TypeScript (for that all important type safety), React Native does not compile down to machine code. Instead, it runs the application’s logic in a JavaScript engine, and communicates with the device’s native code via the React Native bridge, which serves as an interpreter between the two. React Native architecture is typically separated into three key layers.
The JavaScript engine is the first layer. React components, state updates, and the business logic of the application all run on this layer. Code here runs synchronously, but it can make asynchronous calls across the bridge to the native platform when required.
The second layer, the bridge is just a messenger. It handles serialising and deserialising messages between JavaScript and the native platform.
The third layer is the native UI thread and device APIs. This layer receives a request from the JavaScript engine over the bridge, processes it, and sends a response back across the bridge to the engine.
These requests can be for anything, including rendering the user interface, handling gestures and animations, as well as dealing with the device hardware via the device APIs. The device APIs control the hardware on the device, like the camera and microphone, location services and GPS, sensors, push notifications, the file system, and Bluetooth/NFC connectivity.
Just like JSON payloads and responses over a REST API, messages across the bridge require serialisation and deserialisation. High-frequency operations like rendering complex or rapidly changing UI elements, sensors that update hundreds of times a second, streaming camera frames etc all require this serialisation overhead, which generates vast quantities of traffic that can get congested as it waits to cross the bridge. If the bridge gets overloaded, it can lead to dropped frames in animations, stuttering UI, or laggy user interactions.
Let’s be clear here, this is not inherently bad. The fact that some of the largest companies on the planet use applications built in React Native is proof enough that it works at scale. But managing the bottleneck of the bridge does introduce a level of complexity that your development team needs to manage carefully. Meta are clearly aware of this, and the new architecture, seeks to reduce the dependency on the bridge.
2017 saw Google release Flutter, a UI framework for cross-platform app development. Since release, Flutter has been steadily growing into the most serious challenger for React Native’s cross-platform crown. And while Flutter’s plugin ecosystem isn’t yet as large as React Native’s, it is growing quickly — much of it actively maintained by Google — and its global popularity has been rising for years, not just in the US.
This is backed up by multiple sources:
Together, these trends paint a clear picture: Flutter isn’t just growing, it has been more globally popular than React Native for over five years.
Flutter applications are written in Dart, which compiles Ahead of Time (AOT) down to native ARM machine code. This eliminates the need for a bridge entirely, because that compiled machine code can run directly on your device’s CPU. Without this bottleneck slowing down communication between code and device hardware, it’s not only possible, but reasonable to compare Flutter’s performance to fully native apps written in Kotlin or Swift.
Flutter was designed from the ground up to be truly cross-platform, and it certainly shows. The Impeller 2.0 rendering engine frees Flutter from any reliance on your device’s native UI components. Every element on screen in a Flutter app was rendered by Flutter, which means no matter the target device or operating system, a Flutter application will look and behave exactly the same.
In applications with heavy branding, this consistency is absolutely vital. Because every single pixel was drawn by Flutter, your apps aren’t reliant on OEM (Original Equipment Manufacturer) UI widgets that behave differently on devices from different manufacturers or running operating system versions. Your development team have total control.
This all but eliminates OEM quirks, meaning your development team get to spend more time on building your application, and less time figuring out why it works on Samsung, but not on Pixel.
This cross-platform capability doesn’t just stop at mobile development, either. Flutter’s largest selling point is the single, unified codebase. Your team can build one Flutter application, and deploy it to Android, iOS, Windows, Linux and Web, making Flutter exceptionally versatile.
Google is clearly confident in Flutter’s potential to revolutionise mobile development. Major Google products, including: Google Pay, Google Earth and Google Classroom are being powered by Flutter. Companies like eBay, BMW, and Virgin Money are utilising Flutter for their apps as well. With strong integrations with services like Google Cloud, and Firebase, Flutter’s developer ecosystem is growing, and with it, Flutter is gaining more and more momentum with every release.
All of this being said, there has never been, and probably never will be a single “correct” choice for cross-platform mobile development. Both React Native and Flutter are powerful and versatile choices in their own right. Cross-platform might still feel like a bit of a gamble, and both React Native and Flutter are winning hands.
If you’re looking for performance, consistency and a wide-reaching codebase that can target almost any device, there’s just one question you have to ask yourself: Fancy a flutter?
At Shape, our preferred choice for SMEs is Flutter. By building a Flutter application, SMEs can invest once in their product and deploy it to users on every major device, iOS, Android, tablet, web, and desktop, all with a consistent user experience regardless of device model, OS version, or browser. This dramatically simplifies long-term support and ensures businesses only need to maintain one codebase, reducing both development and maintenance costs.
