Performance & Optimization on React Native
Tags: reactnative, performance, mobile, react
Published: 2023-04-18 13:05:15


React Native offers developers various benefits, such as not having to create separate codes for different platforms. But the cross-platform framework comes with its fair share of drawbacks. One of them is worse app performance compared to native development approaches. 

But not all hope is lost. In this article, I’ll try to present the basics of React Native performance optimization.

I will explain the following:

- What is the application performance and optimization?
- How can the optimization process improve your application? 
- Areas to look out for performance and optimization in React Native app?
- More resources to learn from.

So without further ado, let's jump right in!

### **What is the application performance and optimization?**

Application performance refers to the efficiency and effectiveness with which a software application performs its intended functions. This includes factors such as how quickly the application responds to user inputs, how much memory and processing power it requires, and how smoothly it runs without crashing or causing errors.

On the other hand, application optimization involves improving an application's performance by identifying and addressing bottlenecks or other areas where it could be improved. This can involve a range of strategies, such as:

- reducing the amount of code or data required by the application. 
- improving the algorithms used to process data, or 
- optimizing the way that the application uses system resources like memory and processing power.

The goal of application performance and optimization is to ensure that an application is as efficient and effective as possible, both in terms of its ability to perform its intended functions and its impact on the overall performance of the system or infrastructure on which it runs.

### **How can the optimization process improve your application?**

Performance and optimization can greatly improve the overall user experience of an application. Here are some ways in which it can improve your application:

- Speed: Optimizing the performance of an application can significantly improve its speed. When users see that an application is performing quickly, they are more likely to use it and recommend it to others. Faster response times can also improve the user experience by reducing frustration and increasing productivity.
- Efficiency: By optimizing your application performance, you can reduce the number of resources it requires to run, such as memory and processing power. It also means that your app can run on lower-end hardware, making it more accessible to a wider range of users.
- User retention: A well-performing application is more likely to retain users. Users who experience slow load times or crashes may become frustrated and switch to a competing application. By optimizing the performance of your application, you can improve user retention and reduce churn.

Overall, performance and optimization are critical factors in the success of any application. Ensuring your application is optimized for performance, you can provide a better user experience, increase user engagement and efficiency, and improve higher user retention. All of these benefits can ultimately lead to higher profits and greater success for your application.

### **Areas to look out for when looking for performance & optimization on React Native app?**

When it comes to optimizing the performance of a React Native app, there are several areas to focus on. Here are some key areas to consider:

1. Rendering and Layout: React Native relies on the Flexbox layout engine to handle the UI layout. Excessive use of Flexbox can slow down rendering and layout performance. Using the proper layout components and avoiding unnecessary nested views is essential. Also, consider using the FlatList component instead of ScrollView, as it is much more performant when rendering many items.
Also, consider these alternatives to Flatlist ([FlashList](https://shopify.github.io/flash-list/) and [recyclerlistview](https://github.com/Flipkart/recyclerlistview))

2. Network Performance: Poor network performance can lead to long loading times and impact the user experience. Consider using a state management library like Redux to cache and manage the app state also help in reducing network calls.

3. Image Optimization: Images can be a significant source of performance issues in a React Native app. Use the appropriate image sizes, compress images, and use placeholders to improve app loading times.

4. Code Optimization: Optimizing your code can help improve the overall performance of your app. Techniques like code splitting, lazy loading, `useMemo` or `React.memo`, `useCallback`, `useRef` and reducing the number of unnecessary dependencies can all help to optimize your code.

5. Memory Management: React Native apps are prone to memory leaks, so it is crucial to manage memory efficiently. Use the React Native Debugger to analyze memory usage and optimize performance.

6. Device-specific Optimization: Different devices have different capabilities, so it’s important to optimize your app for the devices you’re targeting. For example, you can use the `react-native-device-info` library to get device-specific information and adjust the app’s behaviour accordingly. You can also use platform-specific APIs and optimizations to take advantage of device-specific features and capabilities.


Overall, optimizing the performance of a React Native app requires a holistic approach, and you should focus on the above areas and keep the app's user experience in mind.


### **More resources to learn from.**

1. React Native Performance - Official Documentation: This is the official documentation on React Native Performance. It covers several topics, including layout, images, animations, and more. It also provides tips and tricks to optimize performance and reduce rendering time. https://reactnative.dev/docs/performance

2. The Ultimate Guide to React Native Optimization - Callstack: All you need to know about React Native Optimization in one place https://www.callstack.com/campaigns/download-the-ultimate-guide-to-react-native-optimization?utm_campaign=RN_Performance&utm_source=dev_to

3. Performance debugging on React Native - Medium: How to find the bottlenecks in your react native apps and find where to apply those performance improvement techniques. https://medium.com/geekculture/performance-debugging-on-react-native-80f690936af7

4. 6 Tips to Optimize React Native App Performance -MakeUseOf blog: Take a look at these tips and techniques to optimize the performance of your React Native app. https://www.makeuseof.com/react-native-app-performance-optimize

5. Optimizing React Native performance - LogRocket: Great user experience should be the core objective of any app development. https://blog.logrocket.com/optimize-react-native-performance




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> Cover image credit: Performance Optimizations for React Native Applications — Soshace • Soshace