React Native has exploded in popularity over the last few years as a cross-platform mobile app development framework. It allows you to write mobile apps using only JavaScript and React, two ubiquitous web development technologies. This means you can build iOS and Android apps with the same codebase. 

React Native offers many benefits, but also comes with some downsides to consider. In this comprehensive article, we’ll dive into the pros and cons of React Native to help you decide if it’s the right choice for your next mobile app project.

The Pros of Using React Native

Cross-Platform Code Reuse

The number one advantage of React Native is the ability to build cross-platform apps with maximum code reuse. Typically, native apps are built separately for iOS and Android, requiring effectively two codebases in different languages. 

With React Native, you can write your logic and UI in JavaScript/React once, and deploy it to both iOS and Android. According to Facebook, who created React Native, code reuse can be as high as 90% between iOS and Android. This translates to huge savings in development time and maintenance costs.

Instead of building two separate apps, you’re now building one app for two platforms. Features, bug fixes and updates only need to be written once to reach your entire mobile audience.

Faster Development

The high code reuse, web-like development environment and extensive ecosystem of components allows for much faster app development with React Native compared to native techniques.

Building an app’s UI declaratively with React components is significantly faster than imperative iOS and Android UI code. Hot reloading allows instant UI updates as you code. And with so much existing React Native code and components available, you benefit from the work of thousands of other developers.

Apps that would take months to build natively, can be built in weeks with React Native. For startups and entrepreneurs trying to build an MVP quickly, React Native is a great choice to launch and iterate on your product at lighting speed.

Access to Native Features

While React Native apps are built in JavaScript and React, they are not web-based apps. React Native invokes native UI components and APIs on iOS and Android for you.

This allows access to all the same native platform features and hardware capabilities as traditional native apps, like the camera, local storage, push notifications, gestures, animation and more. With a few lines of JavaScript, you can deeply integrate with each native OS.

React Native is often confused with web-based hybrid app frameworks like Ionic and Cordova. The native runtime and native components make React Native much more performant, smooth and capable. Your users won’t be able to tell the difference between your React Native app and one built natively.

Large React Community

With over 100,000 stars on GitHub, React is one of the most popular open source projects in the world. This means there is a massive community of React developers producing components, tutorials, guides and tools to help build React Native apps.

The React ecosystem will be intimately familiar to any web developer today. Nearly all the knowledge and resources around building responsive web apps in React applies directly to mobile React Native development.

Hiring React and React Native developers is also much easier thanks to the vast community. There’s an abundance of candidates experienced with React from working on web apps and websites.

Code Sharing with Web Apps

In many cases, companies today build a website/web app alongside their mobile apps. Since React Native apps are written in React, sharing code between web and mobile is trivial.

Things like business logic, utility functions, state management, styling and data fetching can all be shared between a website built with React and a React Native mobile app. Components can also be shared when built responsively and with react-native-web.

Code sharing improves developer efficiency since work is not duplicated across platforms. It also leads to better app parity between your website and mobile apps when shared code is powering both.

Popular Brands Are Using It

React Native has been used to build or power mobile apps for some hugely successful and popular brands:

– Facebook – The React Native framework originated from Facebook’s mobile app. Their iOS and Android apps still incorporate React Native code to this day.

– Instagram – Facebook’s photo sharing app contains React Native code for key flows like profiles and feed. Their team has contributed back many performance improvements.

– Discord – The hugely popular VOIP and chat app for gamers uses React Native in its iOS and Android apps.

– Uber Eats – Uber’s food delivery platform is built with React Native for faster development across their global market.

– Tesla – The famous electric auto maker with billions in revenue has built mobile apps embedded in their cars using React Native.

– Bloomberg – The media giant uses React Native in its consumer facing mobile apps to allow cross-platform development.

Hundreds more global brands leverage React Native, which is a testament to its capabilities for building real world apps used by millions. If React Native is trusted by the likes of Facebook and Uber, it can certainly work for your next app too.

Great Performance

A common misconception is that cross-platform app frameworks lead to poor performance. However, React Native compiles to real native app binaries and uses the same fundamental UI building blocks as native platforms.

This means React Native apps perform nearly identically to true native apps built in Swift or Java. Scrolling is smooth, animations are fluid, and layouts are quick. Facebook works constantly to make React Native apps indistinguishable from native ones.

Of course, poor coding practices can lead to performance issues with any framework. But when best practices are followed, React Native performance is excellent for most types of mobile apps, especially on newer/flagship devices.

Future Investments

Facebook has dedicated teams working full time to make improvements to React Native for the benefit of the entire community. Their usage of React Native within Facebook guarantees that time and resources will continue to be invested for years to come.

The pace of new features, improvements and components being added is rapid. Expo allows over-the-air updates to apps without app store review delays. And the React Native ecosystem shows no signs of slowing momentum.

You can be confident building apps with React Native today will lead to an even better, more mature platform in the future. The long term potential makes it worth investing in React skills and code.

The Cons of Using React Native

Of course, while React Native has many positives, it also comes with trade offs. Here are the most common downsides to consider when evaluating using React Native:

Not 100% Cross-Platform

While code reuse can be as high as 90% between iOS and Android, you still need to account for platform differences. Some amount of platform-specific code and styling is ultimately unavoidable. 

Certain APIs and native components may only be available on one platform as well. While React Native tries its best to normalize the differences, expect around 10% of code to still be platform-specific.

Platform-specific code defeats one of the main value propositions of React Native, which is learn once, write anywhere. You’ll need knowledge of native languages like Java/Kotlin or Objective-C/Swift to handle those platform differences.

Rapidly Evolving

The pace of change within the React Native ecosystem can make it challenging to keep up at times. New versions, breaking changes, overhauled APIs and shifting best practices are commonplace. 

Staying current requires constant learning as developers. The volatility can be difficult for larger, more risk-averse organizations to accept. It may take dedicated mobile teams to keep apps up-to-date across frequent React Native releases.

However, the rapid evolution also brings benefits like access to cutting edge capabilities faster than waiting on official platform support. You have to balance the need to stay current against the stability your particular app requires.

Not Ideal for All App Types

While React Native can power the majority of app use cases, it may not be the best choice in a few scenarios:

– Apps with extreme performance needs like 3D gaming or machine learning. Native languages provide lower overhead in some cases.

– Apps heavily reliant on OS-specific APIs and capabilities not yet supported by React Native modules. The framework can’t yet provide access to 100% of all native APIs.

– Apps that need pixel-perfect, completely bespoke UI designs like luxury brands or designers. React Native offers flexibility but doesn’t fully replicate native look and feel in all cases.

– Apps already built natively where full rewrite is not feasible. Integration may work better than wholesale conversion.

For straightforward apps that don’t require specialized native capabilities, React Native will likely be a great choice. But assess if your specific app fits within the framework’s constraints.

JavaScript-Based Development

While being JavaScript-based allows web developers to leverage existing skills, not all mobile teams will be thrilled at having to adopt JavaScript and React. It requires a shift in thinking from imperative UI code to declarative components. 

Game developers or graphics programmers may prefer languages like C++ or Rust for performance reasons too. React Native may receive some internal resistance from certain demographics of low-level native coders.

That said, JavaScript remains the most popular programming language with the biggest community. The benefits of leveraging JavaScript skills typically outweigh any understandable resistance.

Code Ejection Difficulties

A frequent strategy is to prototype or build an MVP with React Native first, then convert to fully native code later if needed. However, “ejecting” to native code may prove difficult, especially for complex apps.

Ideally code could be incrementally converted piece-by-piece while retaining full React Native functionality. But in practice it often ends up an all-or-nothing endeavor. Not being able to smoothly eject code to native modules is a risk to evaluate when considering React Native.

JavaScript Bridge Overhead

React Native’s JS bridge abstraction does come with a slight performance overhead versus direct native calls in some cases. The serialization and asynchronous overhead of dispatching commands between JavaScript and native views may result in occasional lag or jitter.

This overhead is constantly being optimized by the React Native team. And for most apps it’s an acceptable tradeoff for the development speed benefits. But high frequency UI animations or gesture interactions can amplify these issues in some situations.

Should You Build Your Next App With React Native?

React Native brings some clear productivity advantages through cross-platform code reuse, fast development speed, and leveraging web developer skills. However, it’s important to understand the limitations and commitment required to stay current.

Here are some key questions to consider when deciding if React Native is the right choice for your mobile app project:

– How complex is your app UI design? Can it work across platforms or does it need specialized native code?

– Do you require advanced native capabilities like graphics or machine learning?

– Is your team more web developers or more native developers?

– How frequently can you accommodate updating React Native versions and dependencies?

– How critical is extreme, native-level performance for your application?

– Does your company allow usage of rapidly evolving open source software?

If your needs align well with React Native’s capabilities and limitations, it can be a phenomenal tool to build mobile apps faster and reach more users. Existing web teams can leverage their React skills, and you only have to build one app instead of two.

For the right app, built the right way, React Native enables a level of developer productivity rarely seen in native mobile development. But it’s crucial to make an informed decision weighing all the tradeoffs.

I hope this article summarizes the key benefits and downsides to building mobile apps with React Native. Leverage the framework’s strengths like cross-platform code reuse and fast development speed. But design with its limitations in mind, and ensure it aligns to your team’s skills and preferences.

With a thoughtful approach, React Native can help bring quality mobile apps to users much faster and cost effectively than ever before. The combination of native performance and web developer productivity makes it an extremely compelling choice for today’s mobile landscape.