React Native is the latest buzz of the cross-platform app development world. Developers use it for building responsive apps as it increases the speed web and mobile development. Moreover, code written in React Native is reusable for the iOS and Android platforms in your apps. For app development, React Native is considered as efficient as Objective-C or Java. What else do you need then?
Wait, there is something.
Unlike the old native app development languages, React Native’s library does not have ready-made modules for everything. So sometimes, you need to build custom modules on your own. Now the problem with developing custom modules is that you need to optimize them on your own. If not optimized, they will create performance issues for your app.
With the architectural complexity of the app, increases the performance issues in your app.
If your React Native app is also in development phase or performing poorly, read this article to understand how you can optimize its performance. After all, user experience decides the success or failure of your native app, and it heavily depends on app’s performance.
Here is what you can do:
1. Optimize Capabilities of your app
The first step towards optimizing an app is optimizing the architecture of your app. For this, you should carefully find out the features or components which are implemented in the React Native app, although, are not needed. Such extra capabilities are not making your app more efficient, but slowing it down.
Remove all unnecessary app data, controls, views, animations, tabs, navigations and modules from the app. This de-cluttering step will help you come up with a neat and lighter version of the native application.
2. Handle Memory Leakage issues
Native Android applications generally suffer from memory leak issues. It is the condition where multiple unnecessary processes are active and running background, slowing down the speed of your app.
By enabling EDB Integration (Tools > Android) in your Android Studio and monitoring the app, you will be able to detect memory leaks. You may use Perf Monitor for this purpose.
It is a good idea to use scrolling lists over ListView to avoid such leaks.
3. Optimize Images and Multimedia data
Rendering an image is a heavy operation for the memory of mobile devices. High-resolution images, with no optimization technique applied, may increase the load for your React Native mobile app. So to optimize the app, you should optimize this rich data, especially the images.
To do so, you may use different image optimization tools which reduce the size of images to a great extent. Make sure to automatically optimize the images before saving them, if you are allowing the users to upload images. Converting your image files to WebP or PNG format will help a lot here.
4. Use Image Cache Carefully
You may use image caching to quickly load images for your React Native apps, but there is an issue.
Image caching feature works smoothly for iOS devices only.
npm library of Android lets you utilize caching for this Operating System, but do not work as expected.
Chances of cache miss are high, which means that the cached image will fail to load when you will refresh the page. Also, the caching feature is based on JavaScript, which may affect performance adversely. So, it is advised to use this feature carefully.
5. Optimally Re-Render
If you are rendering the props and lifecycles of your app’s components, again and again, your React Native app will suffer. Hence, avoid unnecessary rendering of app components. For that, you should use a function to check if the component is rendered already or not. shouldComponentUpdate function may come in handy here.
If you will keep on re-rendering the components over and over again, reconciler will have to work more and performance of your app will degrade.
6. Optimize Application Size
Lesser is the size of your React Native app, better it will perform. Alongside reducing the unnecessary components from your app, you should avoid saving the third-party modules locally in your app. Instead, use ProGuard to do so. Take note that you should not use the main thread to pass components, which rely on heavy message queues.
Do not forget to optimize the graphical content of your app while trying to reduce the size of your application. Use stable open-source libraries to attain optimal functionality for your app.
7. Maps and Navigations
Navigations and maps work at a slow speed for React Native and there is a reason behind it. Your app is downloading, saving and tracking the complex map data, after all.
We all know that most of the applications have to use map these days, so optimizing the performance of your application is required. We cannot avoid using maps to avoid slogging of our app.
How to do that?
Well, you can eliminate the logging of this map data on the console, which will increase the speed of navigation and boost the performance of your app. Alongside, avoid using ListView for maps. It is better to make use of FlatList here.
8. Avoid Initializing Multiple Threads at Once
React Native do not allow running multiple threads at once. If you will initiate two or more heavy actions to happen at once, it won’t work smoothly. For example, if you are letting a user switch on the camera and send a voice message parallel, the app will hang or crash.
Now, in order to avoid such crashes or halts, you will have to code your app accordingly. Do not let application’s end-users perform multiple operations together. Code it in a way that next thread should be invoked once one thread is executed successfully already. Optimizing the performance, it will also make your app robust and reliable.
9. Handling JSON Data
JSON data is generally fetched from distant URLs which rely upon different servers. If your mobile app is requesting and fetching this data, it will have to wait for the successful retrieval of this data. This operation will result in reduced speed for your React Native App, hence, degraded performance.
To avoid this issue, do not download complex JSON data but simplify it for fast retrieval.
10. Controlling the Orientation of Screen
You may develop React Native apps with animation, gaming capabilities, picture-capturing efficiency and more. Now if your application has any of these features and you allow an instant change in screen orientation, your app may not work smoothly. If the user will try changing the orientation from portrait to landscape and vice-versa frequently, the app may get closed or crash.
To avoid this issue in Android-specific apps, you can use react-native-orientation which does not work for iOS apps. For making orientation switching work properly for iOS too, use the root view controller instead.
Conclusion
Performance of an app plays a critical role in deciding the efficiency of an app. If your app is not well-optimized, it will result in bad user experience and unsatisfied users. Frustrating people, it will drift them away from your app. So always consider it an important task to optimize and test React Native app, before you launch it. Hire React Native developers so that they can take care of it on your behalf.
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