Essential Techniques to Reduce React Native App Size for Better Performance

Mobile app users today expect lightning-fast performance, seamless experience, and minimal storage usage. If your React Native application is sluggish or takes up too much space, users are likely to abandon it quickly. At Siddhi Infosoft, a leading React Native Development Company, we understand that optimizing app size is crucial for delivering high-quality apps that stand out in competitive app stores.

In this blog, we’ll explore essential techniques to reduce React Native app size without compromising on functionality or performance. Whether you’re just starting or looking to fine-tune your existing app, these tips can make a significant difference.

Why React Native App Size Matters

App size directly impacts:

• Download speed – Larger apps take longer to download, especially in areas with slow internet connections.
• Install rate – Users may abandon an app install if it’s too large.
• Performance – Bloated apps may run slower, consume more memory, and crash more frequently.
• User retention – Storage-conscious users may uninstall heavy apps over time.

As a React Native Development Company, we focus on delivering lean, efficient apps that enhance user satisfaction and engagement.

1. Use Proguard for Android

Proguard is a powerful tool that shrinks, optimizes, and obfuscates your code. By eliminating unnecessary classes, methods, and attributes, it significantly reduces the overall APK size.

How to Enable Proguard:

1.Open your android/app/build.gradle.
2.Set minifyEnabled to true in the release buildType:

buildTypes {
    release {
        shrinkResources true
        minifyEnabled true
        proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
    }
}

Don’t forget to test thoroughly, as Proguard can sometimes remove code that appears unused but is critical.

2. Remove Unused Dependencies

One of the most common mistakes in React Native Development is including unnecessary third-party libraries. Every extra package adds to the bundle size.

Tips to Reduce React Native App Size:

• Review your package.json file and uninstall any libraries that are no longer being used.
• Replace large libraries with lightweight alternatives.
• Use modular libraries instead of full packages.

At Siddhi Infosoft, our React Native development services include regular code audits to eliminate bloated dependencies.

3. Optimize and Compress Images

Images often account for a large portion of the app size. Optimize them to reduce weight without losing quality.

Techniques:

• Opt for modern image formats such as WebP to replace traditional PNG or JPEG files
• Reduce image file sizes by compressing them with tools like TinyPNG or ImageOptim
• Load images via URL (when possible) rather than bundling them

Also, avoid unnecessarily high-resolution images unless required for specific devices.

4. Use Hermes Engine

Hermes is an open-source JavaScript engine specifically designed to enhance React Native performance on Android by reducing app size, improving startup speed, and lowering memory consumption.

To enable Hermes:

1.Go to android/app/build.gradle.

2.Under project.ext.react, set enableHermes: true.

project.ext.react = [
    enableHermes: true
]

Hermes is especially effective for mid- to large-sized apps. At Siddhi Infosoft, we recommend Hermes integration as part of our performance optimization strategy.

Read More: https://www.siddhiinfosoft.com/blog/laravel-best-practices-web-development/

5. Enable Resource Shrinking

Unused resources such as drawables, strings, or layouts can unnecessarily increase the APK size and should be removed to keep the app lightweight.

Make sure shrinkResources is set to true in the release configuration (covered in Proguard section).

This works hand-in-hand with Proguard and can reduce your APK size significantly.

6. Optimize JavaScript Bundle

Your JavaScript bundle size plays a major role in app performance.

Best Practices:

• Remove console logs from production builds.
• Use dynamic imports to split code.
• Use babel-plugin-transform-remove-console for removing console logs:

npm install –save-dev babel-plugin-transform-remove-console

Update .babelrc:

json
CopyEdit
{
  "env": {
    "production": {
      "plugins": ["transform-remove-console"]
    }
  }
}

This keeps your production builds clean and lightweight.

7. Lazy Loading of Components

Don’t load all components at once. Lazy loading enhances initial load performance by loading components only when needed, which also helps reduce overall memory usage.

Use React’s React.lazy and Suspense:

js
const Profile = React.lazy(() => import('./Profile'));

}>

This technique is especially helpful in large apps with multiple screens and complex components.

8. Avoid Inline Requires (when appropriate)

React Native’s inlineRequires can speed up launch time by deferring module loading until they’re needed.

Enable it in metro.config.js:

js
module.exports = {
transformer: {
getTransformOptions: async () => ({
transform: {
inlineRequires: true,
},
}),
},
};

Note: Inline requires reduce initial bundle size, but test thoroughly—especially if you’re using libraries that require early loading.

9. Use Lottie for Animations

Animations often involve heavy GIFs or videos. Instead, use Lottie, which renders animations using lightweight JSON files exported from Adobe After Effects.

This significantly minimizes the app size while delivering fluid and high-quality animations.

bash
npm install --save lottie-react-native

Integrating Lottie is part of our advanced UI/UX strategy as a React Native Development Company.

10. Split APK by ABI (Android)

Different Android devices use different architectures (ARMv7, ARM64, x86). Instead of building one APK for all, you can generate split APKs for each architecture.

In android/app/build.gradle, add:

CopyEdit
splits {
abi {
enable true
reset()
include "armeabi-v7a", "arm64-v8a", "x86", "x86_64"
universalApk false
}
}

This reduces the size of each APK by shipping only the required native libraries.

11. Remove Debugging Tools in Production

Tools like Reactotron, Redux Logger, and Flipper are invaluable during development—but must be removed from production builds.

Tips:

• Use environment variables to include dev tools only during development.
• Strip out debug-only code using Babel plugins or manual flags.

Failing to remove them not only increases app size but may expose sensitive logs.

12. Use App Thinning for iOS

App Thinning in iOS helps reduce app size on users’ devices. It includes:

• Slicing: Creates optimized, device-specific versions of your app to reduce its size on each device.
• On-demand resources: Loads resources when needed.
• Bitcode: Apple recompiles the app to optimize for specific devices.

Make sure your Xcode project is configured to support these.

13. Monitor and Analyze Build Size

Use tools like:

• react-native-bundle-visualizer – to visualize and analyze JS bundle size.
• apk analyzer (Android Studio) – to break down APK size by components.

Tracking size regularly helps you catch unexpected increases.

14. Choose the Right React Native Development Company

Partnering with the right React Native Development Company ensures your app is optimized from day one. At Siddhi Infosoft, we offer comprehensive React Native development services that prioritize performance, size optimization, and scalable architecture.

We don’t just build apps—we engineer efficient digital products that help you gain a competitive edge.

Conclusion

Reducing your React Native app size is not just a one-time task—it’s a continuous process of refinement, testing, and optimization. From removing unnecessary dependencies to using Hermes and Proguard, there are multiple proven techniques that can drastically cut down app size and improve performance.

At Siddhi Infosoft, our team of React Native experts is committed to delivering apps that are fast, functional, and lightweight. Whether you’re building a new project or refining an existing one, our React Native development services are tailored to help your business succeed.

Ready to optimize your React Native app?

Connect with Siddhi Infosoft—your trusted React Native Development Company—and let’s build something remarkable together.

Frequently Asked Questions (FAQs)

1.How much difference does app size really make for users?

A lot more than most developers think. Smaller app sizes mean faster downloads, quicker installs, and less chance of uninstall due to storage issues. Especially in markets where users rely on lower-end devices or metered internet, even 10MB can make or break a user’s decision to keep your app. Plus, lighter apps generally perform better on slower networks.

2.Is Hermes really worth enabling in a React Native project?

Yes—especially for Android apps. With Hermes, apps run smoother thanks to optimized size, faster loading, and better memory handling. However, it’s not a universal fit—you may need to fine-tune your setup to get the best results. You may need to tweak your build and test for compatibility. Still, for most apps with significant business logic or user interactions, the performance gain is worth the integration effort.

3.What’s the best way to identify what’s bloating my React Native app?

Analyze your bundle with utilities like react-native-bundle-visualizer or the APK Analyzer tool in Android Studio for detailed insights. These help you see which assets or libraries are adding weight. Often, it’s unused dependencies, oversized images, or unnecessary fonts. Doing a deep-dive audit once every few sprints is a good habit to catch bloat early.

4.Can I use Proguard and Hermes together?

Yes, and they complement each other well. Proguard handles code shrinking and obfuscation on the Java side, while Hermes optimizes your JavaScript engine. Together, they can shave off several megabytes. Just be sure to configure your Proguard rules properly so essential parts of your codebase don’t get stripped away.

5.Are image formats really that big of a deal?

Absolutely. JPEGs and PNGs add up fast—especially if you’re bundling multiple resolutions. Switching to WebP can cut image sizes by up to 30–50% without compromising quality. Also, always compress images before bundling. Developers often overlook this step, but it’s one of the easiest wins in app size optimization.

6.Can Siddhi Infosoft help optimize an already built React Native app?

Definitely. Whether your app is still in development or already live, our team can step in, audit your current build, and implement smart size-reduction strategies—everything from lazy loading and asset optimization to Hermes integration and Proguard tuning. We help you ship a lighter, faster app without cutting corners.