React Native is a popular cross-platform mobile app development framework used by many companies such as Facebook, Discord, Tesla, and Coinbase. However, to truly leverage all the abilities of React Native mobile app platform, you should be clear about the various tricks and tips to optimize React Native app performance. Understanding the nuances and best practices of optimizing performance in React will help you save development costs, improve code efficiency and make error-free, scalable, and robust cross-platform apps like the popular apps mentioned earlier.
Managing React native performance optimization techniques and following all the best practices can be difficult and time-consuming. Hence, if you are looking to build an app but don’t have the required resources or time to invest in its optimization, you should hire React Native developer who is experienced and knows how to maintain and improve React Native app performance.
React Native App Performance Issues and Optimization Techniques
Before discussing the React Native app optimization best practices, we should look into the most common React Native app performance issues and bottlenecks that developers generally face during React Native app development process –
1. Memory Leaks in Android Lists
Performance Optimization Technique for Memory Leaks in React Native
When building a music app or any other app that requires such scrolling, use FlatList or VirtualizedList in place of ListView. Developers can also use another alternative known as SectionList.
2. Poor App Bundle Size and Android Performance
One of the biggest drawbacks of React Native android app development is its overall app size since it’s a framework that depends majorly on third-party libraries, creating multiple screens and other third-party sources to operate. This then impacts the overall functioning of the Android app as well.
Performance Optimization Technique for Bundle Size and Android App Optimization in React Native
- Creating reduced APK files for specific architectures is a great workaround for solving app size issues in React Native. The app automatically fetches the relevant APK file as per the users’ phone architecture by setting this up. This helps eliminate the need to keep JSCore binaries in your app or hold multiple architecture variations, reducing the overall app size.
- Use effective tools like ProGuard to reduce Android app size
- Always compress and optimize graphic elements and multimedia content
- Instead of saving raw JSON data, you should convert it into static object IDs
3. Navigation Issues
React Native, though excels in many aspects of development, navigation is one aspect where it lacks majorly. The React Native community has been working on resolving these issues and has managed to fix many aspects, but it still is a persistent performance bottleneck. Inefficient navigation can make it difficult for users to access all app features and interrupt their user experience, making them abandon your app and switch to another.
Performance Optimization Technique for Navigation Issues in React Native
React Native has four different approaches to building proper navigation –
- Navigator – best suited for small apps/prototype development
- Navigator iOS – proper navigation optimization solution for iOS
- React Navigation – popular navigation method that would work for most types of React Native apps
- Navigation Experiment – often used in large-scale apps. However, it isn’t the most user-friendly navigation library
4. Slower App Launch Time
React Native apps often have a slower app launching time than other frameworks. This happens when your React Native app has too many dependencies and is built using slow components. Loading all the dependencies on app startup time consumes many resources, delaying the app launch time.
Performance Optimization Technique for Slower App Launch Time issue in React Native
Try reducing the number of dependencies in your React Native app and using faster components. Avoid elements that are known to increase app launch time like Object. Finalize. Overusing finalizers can create memory shortage errors, so use them in moderation.
Alternatively, you can use React Hermes, an open-source JS engine designed to improve app startup time for React Native apps. It also decreases memory usage resulting in smaller app size.
5. Absence of support for Multithreading
React Native doesn’t support multithreading (the ability to run multiple processes simultaneously). This means other components need to wait in line while one component gets rendered. Hence if you are trying to build an app that might need to implement multiple features together, like a streaming service that provides a live chat option and live stream feed together, higher-end smartphones might be able to handle such requests, but lower-end phones will suffer.
Performance Optimization Technique for Multithreading Absence issue in React Native
You can hire React Native developers that know how to build reliable extensions that can enable multithreading in React Native apps. It will allow you to set up custom functionality that a normal react app wouldn’t have. These extensions can be written in Objective-C, Swift, Java, or other languages that support multithreading. Always test your extensions on a real device to check for issues and memory limits.
React Native Optimization Best Practices
Now that we have discussed some of the common React Native app optimization challenges and their solutions, we can focus on some other best practices to optimize React Native apps –
1. Removing all console statements
Console statements play a major role in the production of React Native app development. They help debug JS code; however, their purpose is only limited to development. If you don’t remove them from your React Native app before bundling, they can cause serious performance bottlenecks. Although there are plugins to remove console statements from your React Native app, it is better to get rid of them manually, thus reducing the overall dependencies of your React Native app and resulting in better performance.
2. Making use of React.memo
React.memo is used in functional components to replicate the capabilities of React PureComponents in-class components. It helps prevent unnecessary re-renders, which can help optimize your React Native app. Using this method in moderation is important and should not be used to stop all re-rendering that doesn’t impact the overall app performance.
3. Adjusting and Optimizing Image and other multimedia files
This is not just a React Native app optimization best practice, but for any mobile app, multimedia content takes up a lot of space and are important elements to appeal to customers as well. Hence, they can be considered to be necessary evils. Although, unlike web apps, React Native comes with an Image component capable of handling one image perfectly; however, it also falls short when you need to use multiple high-res images.
To solve this issue, you should edit the image according to the size and scale you need to use before loading them into the app. You should also cache images locally where their local cache can be used for later requests. However, this ability is only available on iOS and not on Android. Alternatively, you can also use more mobile-friendly image formats such as PNGs in place of JPGs or WebP format, which can reduce the space taken by images to 25-34%.
4. Declutter unnecessary features and libraries
All the React Native app libraries and features you use to build your React Native app should justify their presence and the footprint they leave on your overall app size. When starting a React Native app development project, it is possible that you don’t realize how overcrowded your React Native app is getting. However, it is important to keep an active check on all the features and libraries you add and question yourself objectively if some of those features and libraries are unnecessary and remove them if the answer is yes. This way, you can improve the overall app performance significantly.
These are some of the best ways to optimize your React Native apps and solve some of the challenges and limitations of React Native most efficiently and practically. Follow them and get the best performing React Native app for your app requirements.