Quick Summary

React Native is one of the most popular app development frameworks that are being used by developers to develop desired mobile applications quickly. Are you trying to get the answer of how to optimize react app? You are at the right place. Just like any other framework the React Native framework also has some drawbacks and the community of developers is constantly updating it. There are some popular React Native applications like Facebook, Netflix, Instagram, and many more. If you are wondering about React Native performance then in this blog you will get all the answers.

React Native Performance – What’s the real cause behind performance issues?

You need to understand the main reasons that are affecting the React Native App performance. Mainly three factors can affect the performance of your React Native application. The React Native performance of the application depends upon the factors like Native Thread, JavaScript Thread, and Bridge.

• Native Thread helps to run the programming languages like Objective C, Swift, Java, and Kotlin.

• JavaScript thread helps to run different types of animations and UI components using JavaScript.

• Bridge works as the mediator between the Native and JavaScript thread.

The real cause behind the React Native app performance issues is that the passing of the components can be a complex process. To avoid this React Native performance issue in the application, you need to make sure that the passing of the components through bridges is less. There are plenty of benefits of React Native and the main benefit is that developers don’t need to create separate codes for various platforms like Android and iOS.

Using React Native Slowlog to optimize performance issues in React Native

In the above section, you understood the real cause of React Native performance limitations. Now let’s understand how developers optimize React Native app performance using the Slowlog tool. The Slowlog tool is suitable to solve bigger performance problems in React Native and it also notifies the operations of the application that are slow. Before using any tools to optimize performance issues in the React Native apps, developers need to check the Slowlog first. It can be added in a constructor like slow log (this, /.*.).

Common React Native performance issues in Android

Memory leak in Android lists

It is a very common issue that users face the problem of Memory leaks in React Native applications. By locating these memory leaks you can easily improve react native android performance by eliminating them. When users are scrolling any entertainment application for several pages it is quite obvious that performance will be decreased as it consumes too much RAM. Android applications can be divided into two parts: native and JavaScript or React Native part. Passing the data between these parts is a time-consuming process.

Solution: Fixing memory leak due to listview

The issue of memory leak in react native mobile applications can be solved by using VirtualizedList or FlatList. Traditionally, ListView is used to display the data but it also decreases the app performance and RAM won’t be cleared if the application is running in the background. FlatList is the perfect choice when you want infinite scrolling of pages and smooth rendering performance. Some developers even use SectionList because it is a high-performing interface that provides a better scroll experience.

Avoid Passing Functions Inline as Props

When you pass a function as a property to a component, it’s best to avoid doing it directly in the property. Otherwise, the component may re-render, even when nothing has changed. To prevent this, it’s better to define the function as part of the component instead. This way, the function doesn’t need to be created over and over again, making the component faster and more efficient. By following this tip, you can ensure your components work well and provide a good experience to the user.

Application size and performance on Android

The size of the application directly affects the performance of the android application. Many android applications depend upon third-party libraries, APIs, and many more. As developers add these resources, the size of the application will increase and performance will be decreased. To get an optimized and well-performing React Native app, developers can implement the method given below.

•  Reduce the size of the image and other graphical elements. Try not to store raw JSON data and try to convert it into static object IDs. Try to optimize different types of third-party libraries, APIs, and native libraries that are used in the android application.

React Native navigation components in Android

To constantly improve React Native performance, the community of developers is constantly providing updates to ensure that mobile applications can run flawlessly. The developers can easily create React Native app by using different types of navigational components. The main core development team of react native tries to eliminate different types of inconsistencies between JavaScript and Native threads to avoid delay. Here you can see some react native navigation components that can be used while building android applications.

Navigator

Navigator is a fully JavaScript-based navigation component and some developers don’t like to use it because sometimes it doesn’t provide better performance. The main performance issue in the navigator is that whenever developers try to add new features to the application, it doesn’t perform well. Handling of all the operations will be done by JavaScript thread and is not an ideal choice when you have the same code between iOS and Android.

NavigatoriOS

NavigatoriOS is created as a native platform for iOS and it’s not suitable for you when someone wants to use it on android. So it can be the best option if you are creating an iOS application because it is suitable to work around the iOS platform only.

NavigationExperimental

NavigationExperimental is one of the best navigators that can be customized by the developers but many developers find this navigator hard to use. While using NavigationExperimental you can still use the previously mentioned navigation components in your application and the plus point is that the application has a simple UI that performs well.

React Navigation

React Navigation offers a configurable JavaScript re-implementation of the native views because it is a much better option for react native navigation. When you need to implement your navigation logic inside redux this React Navigation offers routers that are quite helpful. It can serve as an alternative to all the navigational elements mentioned above.

Rendering Native views faster

Developers will take full advantage of the virtual DOM feature of React Native and optimize the rendering components of JavaScript. This reduces the quantity of information transferred across the bridge and enhances rendering and synchronizing. It was initially built for JavaScript-based web applications but nowadays many applications are using the Diff algorithm to improve the performance of the application.

Delay in updating UI in Android

It has been mentioned earlier that React Native shifts all the complex functionalities to the JavaScript thread and that delays the process of updating the UI of android applications. Because of such complex operations, android applications don’t manage to provide the best performance. Whenever the main JavaScript thread is not free, different types of animations related to navigation won’t run. The core development team of React Native has said that they are working to improve this updating UI issue in Android applications.

Improving React Native app Launch time

The users will stop using the React Native app if it is taking too much time to open. You can also face the issue of slow app performance because of the default implementations of React Native. To improve the launch time of the React Native-based application you need to use an element named Object. finalize. Finalizers should be used carefully because they create huge dependencies and it can slow down the launching time of the application.

Image caching in React Native for Android

Some libraries are used to solve the issue of image caching in React Native for the android app but it’s not very effective because android applications still require improvement. Whenever the page of the android application is refreshed, it will reload the images. It takes too much time and affects the performance of the application. If you use react-native-cacheable-image then dynamic caching is possible and it will improve the performance of react native android app.

Use Hermes

Hermes is a JavaScript engine designed for mobile applications that aims to reduce download size, memory usage, and app load time.  If you enable hermes then it is quite useful in react native optimization. Enabling Hermes can be a great way to optimize the performance of your app. Connect with a professional Native App Development company that provides various services to help you and enable Hermes on both iOS and Android, ensuring that your app runs smoothly and efficiently on both platforms.

React Native Image Optimization on Android

It is essential that you should add responsive images to your application otherwise may feel that your application is not providing the best performance. For React Native Image Optimization you should use smaller images that can be easily requested from the server. Try to use JPG images in the application because it reduces the memory footprint. You can even use WebP format for images because it reduces loading time.

React Native app performance: Evaluating performance issues in iOS

Animating the size images for different UI view

Whenever a user opens a react native application, the height and width of the image will be scaled according to the size of the screen. This process takes a lot of loads and it is one of the main reasons why the app takes time to load. To ensure that React Native applications can quickly load images for different types of UI views with the help of a component named onLoad.

Multi-threading issues in React Native

One of the main issues in React Native is that it doesn’t provide support for multithreading. Whenever one component is rendered in React Native, all other components have to wait until the rendering process of the first component is completed. You can create extension code that works as a bridge between React Native and Native components to deliver a best-performing solution.

Infinite Scrolling: performance optimization for React Native

One of the best ways to provide optimization for the React Native app performance is by infinite scrolling. You can easily implement infinite scrolling through FlatList, ScrollView, and ListView. ScrollView helps to render all the feed elements together. ListView provides additional rendering options that can be used to render the images. FlatList is being used in different types of React Native versions.

Progressive Image Loading in React Native iOS

The procedure of loading images in React Native iOS can be costly, that’s why developers open and build different types of components. Pass a full-size image to display by simply using the Image component. Developers can even pass a thumbnail to show when the user is trying to load a full-size image.

Image Placeholders in React Native

React native image component doesn’t provide the best experience for the users. It is one of the main reasons why you should use the progressive loading technique for mobile applications. In this technique, developers will use a tiny thumbnail to display on a placeholder. Plus, they will use the progressive image component to load the thumbnail first.

Using cleaned console.log statements

To improve the performance of React Native applications you need to run console.log() statements because it is important to debug your React Native application. Multiple statements can decrease the performance of the react native applications and that’s why you should remove all console calls with the help of a plugin named babel.

Handling Animations in React Native

React native app performance also depends on the animations of the android application. It provides different types of animated APIs to run some of the stock animations like layout transitions. If you use third-party APIs and libraries then React Native performance of the android application will decrease. Sometimes because of these animations, the battery drains much faster.

Heavy computation work on the JS thread

Whenever you try to do any heavy computation work in React Native application, there is a huge chance of frame drops. To get the best-optimized performance of React Native applications you need to use different types of animated libraries with a Native driver. By following this procedure you can optimize your application.

Conclusion

Hope that in this blog you have understood all the details about React Native performance. In this blog, you have seen ways to increase the performance of your app. You should hire React Native developers if you want the most appealing mobile application for your business. You can see the points that you should avoid to make sure that you have a well-performing and fully-optimized React Native application.

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