Best Tricks to Speed Up Your React Native App

How to Make Your React Native App Run Faster

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Undoubtedly, React Native has quickly gained popularity in the past few years, but some developers are still wondering how to make their React Native apps run faster.

Though React Native can be pretty fast, it’s not always as fast as native code would be. However, with some serious performance optimization, you can easily speed up your React Native mobile app.

But the question is how would you make it run faster, especially if you have never done it before?

Don’t worry! We have covered some simple and amazing tricks that you can use to make your React Native app run faster and enhance the performance of the app. In this guide, I’ll take you through the basic and advanced optimization tricks that anyone can try to speed up the React Native app. No matter, whether you’re an experienced developer or someone who has never even set up a React Native project, these tricks are simple to implement.

Keeping in mind the skills of developers and beginners, we have tried to cover all such tricks that are in the form of JavaScript modules. These tricks are easy to install, or you can copy the code into your own application. There are also ways to hire a React Native app developer to leverage some React Native optimizations that don’t require you to change any code at all!

From learning how to get your app running on Android devices and iOS simulators to speeding up your animations, this guide will help you take your React Native app from zero to hero in no time at all!

Let’s take a look at some ways to make your React Native app run faster!

Simple Ways To Speed Up Your React Native Mobile App

1. Fixing Slow Rendering

One of the most common issues that people run into with React Native is slow rendering. The reason for this is that React Native does not use a traditional DOM as web browsers do. Instead, it uses a virtual DOM which is a JavaScript representation of the native view hierarchy.

When a user interacts with a React Native application, the changes are batched and then sent over to the main thread where they are applied. This process can be slow if there are many elements that need to be updated.

Here are some tips to fix the app rendering issues:

• Use the Chrome performance tool to identify which parts of your app are slow.
• Check if you’re using unnecessary, complex components.
• Make sure you’re not making too many style changes within a single render pass.
• See if you can create simpler versions of complex components.
• Use the shouldComponentUpdate lifecycle hook to prevent unnecessary re-renders.
• Use the memoize function to memoize expensive calculations.
• Make sure you’re not doing too much work on the main thread.

2. Recheck Style Measurements

Changes to the layout or positioning of elements on the screen are the most common performance issue in React Native, which is why style recalculations happen so often. To avoid this, figure out what is causing the style recalculations and find a way to stop it.

To start, here are seven ways you can make sure that it doesn’t happen:

• Forget About animations: Animations may be fun, but they’re also expensive for running performance for your React Native app. Make sure you don’t have any animations if possible. The exceptions would be low-power UI effects like parallax scrolling or other motion effects that require minimal animation like inertia scrolling.
• Use Static Layouts: Static layouts help reduce style recalculations by only rendering new parts of the view as they come into view, rather than every time there’s a layout update like with dynamic layouts. Also, you can consider hiring a React Native developer to assist you further.
• Using static layouts will also allow you to set up rendered props and memoized styles without worrying about updates. A downside is that they force the developer to organize their components in an unnatural way. In addition, this provides predictable interactions among components and eliminates hard-to-find bugs caused by order dependency.
• Set up shouldComponentUpdate() correctly: Using shouldComponentUpdate() incorrectly will cause some extra work for your computer to do each time it does a layout calculation, which will slow things down and ultimately result in poor performance. Use shouldComponentUpdate() properly and set it up at the right level of granularity depending on how much logic your component has inside of it — no more, no less!

For ready reference, we are sharing a code guide:

3. Using Hermes To Uplift Performance

Hermes is an open-source JavaScript engine specifically built to improve the performance of mobile applications. It is available for Android and is compatible with React Native 0.60.4 version and higher.

Additionally, Hermes is available for iOS with versions 0.64-RC.0 and above. The prime role of Hermes is to reduce the download size, the memory footprint, and the time needed for the app to become interactive. Making use of Hermes in a React Native app can help you enhance the performance of the app and enable you to ensure a better user experience.

Activate Hermes for Android by opening build.gradle and adding the following line:

def enableHermes = project.ext.react.get(“enableHermes”, true);

To enable Hermes for iOS, open Podfile and use the below command line:

use_react_native!(:path => config[:reactNativePath], :hermes_enabled => true

4. Make Use of Lazy Loading To Improve Startup Time

Lazy loading is a concept used in software development to load resources on demand. In the context of React Native, it means loading components only when they are needed. This can be done using a library like React Loadable or by code splitting your app into smaller pieces.

The primary goal is to improve performance by reducing the amount of code that needs to be parsed and executed on the initial load. When done correctly, lazy loading can significantly improve the startup time of your app.

For better usage, you can consider hiring a mobile app developer in India. Using React Loadable, we were able to cut down our loading time from 3 seconds to less than one second. If you don’t want to use a third-party package, you can also accomplish this with manual code splitting.

For example, if you have an app component with two screens and five scenes total (e.g., App-A screen + 5 scenes). In that case, consider creating an App-A screen with all five scenes as children. After that, create four separate files for each scene inside the directory: App-A/Scenes/scene1, App-A/Scenes/scene2, etc.

Next, create an index file called App where you will import these files instead of importing each individual scene. Importing everything at once may seem daunting at first, but let’s say there are 100 screens and 1000 scenes — that would mean 100 imports per scene, which adds up quickly!

5. Make Use of InteractionManager in React Native Apps

The InteractionManager provides a way for developers to queue and manage interactions such as touch events or navigational transitions. By default, interactions are handled synchronously. This can lead to dropped frames and jank. InteractionManager allows developers to specify when an interaction has finished, so that long-running work can be scheduled accordingly.

In order to use InteractionManager, you need to wrap any code that could cause a jank in an interaction callback. Once you have wrapped the code, any interaction will trigger the callback, allowing you to schedule the long-running work.

Here is a code line you can directly implement in your existing code:

InteractionManager.runAfterInteractions(() => {
// …long-running synchronous task…
});

6. Optimizing Your React Native App Codes

React Native is one of the most popular frameworks for developing mobile apps. It is loved by developers for its ease of use, flexibility, and performance. Most organizations choose to hire a mobile app developer to build a React Native app just to avoid performance issues. However, even the best-optimized native app can suffer from performance issues.

Here are some tips to help you optimize your React Native app code and make your app run faster:

• Optimize your code so that it runs more efficiently. This can be done by minifying your code and using a tool like Babel to transpile it down to ES5
• Another way to improve performance is by using caching and pre-compiling assets.
• To improve the performance of a React Native app, start by optimizing the code. This can be done by minifying the code, reducing the number of dependencies, and using a performance-focused coding style.
• Minifying the code means removing unnecessary characters, such as whitespace, from the source code. This can be done using a tool like UglifyJS.
• Reducing the number of dependencies means making sure that your app only loads the code it needs to run. This can be done by tree-shaking unused code or using a module bundler like webpack.
• Using a performance-focused coding style means writing code optimized for performance from the start.

Finally, make sure you’re not making too many network requests and that you’re using a performant JavaScript engine like V8.

Good One: Top App modernization trends in 2024

7. Removing Console Statements in React Native App

In order to make your React Native app run faster, you’ll want to remove any console statements. Console statements are used for debugging purposes and can slow down your app. To remove them, you can use the Babel plugin called babel-plugin-transform-remove-console. This plugin will remove all console statements from your code.

Wondering how it works? Here is a quick guide:

Step 1: You can install it by running npm install — save-dev babel-plugin-transform-remove-console in your terminal or by using Yarn (yarn add — dev babel-plugin-transform-remove-console).

Step 2: Then, you need to tell your project that this is a dependency of its environment by adding babel-preset-react : presets/env.

Step 3: The last step is updating your .babelrc file with plugins: } plugins: }}

Hopefully, these simple steps will help you enhance the performance of your React Native app. While practicing these tricks, many of you may have thought, “What if we consider developing a React Native app right from the scratch?” Where to hire the best React Native App Developers in India? How much does creating a React Native app with optimum performance cost? If you are also interested in this, then here is the answer to the question…

How Much Does It Cost to Create a React Native App From Scratch?

The cost of creating a React Native app from scratch can be as low as $10,000 and as high as $50,000+. Surprised to know why there is a huge difference.

Here we will tell you the secret mantra…

The average cost of the app development is depending upon various factors such as c complexity of the app, technologies, app development team, UI/UX designing, testing, features, and functionalities. These factors greatly vary according to the business requirements. Since every business is different, though, they require different solutions that are specifically tailored to their needs.

So, depending on such complexities, the average price of app development can go up and down accordingly. If you already have an idea to create a React Native app, it is worth discussing it with the experts to get cost estimations. You can book a free consultation slot for the discussion!

In a Nutshell

There are many aspects of React Native apps that can affect their performance, including large images, heavy computations, and unnecessary render calls. However, the good part is that you can hire a React Native app developer to quickly overcome those issues by following the best techniques and tricks. Moreover, the experts will be there to use the best choice of tools and methodologies to ensure optimum app performance without having to implement so much coding.

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