How to Reduce React Native App Size Practical Tips That Work

Introduction

App size may not be the first thing developers think about, but it directly affects how users interact with your product. A large app takes longer to download, consumes more storage, and sometimes gets abandoned before it even opens. For teams targeting emerging markets or users with limited data, size becomes a deal breaker.

React Native apps often grow larger than expected because they bundle native code, third party libraries, and heavy assets together. The good news is that there are practical ways to cut down the size without sacrificing its features.

In this guide we will look at the main reasons React Native apps get bloated and walk through proven techniques to make them leaner. The goal is not just a smaller number on the store listing but a faster, more efficient app that feels easier for users to adopt.

Why React Native Apps Get Large

Before trimming the size of your app, it helps to understand where the extra weight comes from. In most cases, the problem is not React Native itself but how the project is structured and what it carries inside the package.

1. Extra dependencies

Every time you add a third party library, you also add native code, JavaScript, and sometimes assets that get bundled into the final build. Unused or outdated packages are one of the biggest contributors to app bloat.

2. Heavy images and media

Uncompressed images, large PNGs, or unnecessary video files can quickly inflate your build size. Even fonts with multiple unused weights add up over time.

3. Debugging code in release builds

If you do not strip out development tools or debugging code, they remain inside the release version. This adds size without providing any benefit to end users.

4. Lack of optimization in packaging

By default, builds often include resources for every device architecture (arm64, x86, etc). Shipping one universal build makes the app larger than it needs to be.

5. No resource shrinking

When unused resources, icons, or layouts are not cleaned up, they get bundled anyway. Over months of development, these leftovers can quietly push the size up.

These issues may seem small on their own, but combined they can make a React Native app noticeably heavy. The next step is learning how to address them with targeted optimizations.

Practical Tips to Reduce React Native App Size

There is no single switch that makes your React Native app smaller. Instead, you get results by applying several small optimizations. Here are the most effective ones to start with:

a. Remove unused dependencies

Unused or outdated libraries are silent app bloaters. Audit your project with:

npm ls

Or

yarn list

Remove packages that are no longer required and replace heavy ones with lighter alternatives when possible. Even small savings here add up.

b. Optimize images and assets

Media files often account for a large part of app size. To reduce their impact:

• Use formats like WebP instead of PNG or JPEG.

• Compress images with tools like TinyPNG or ImageOptim before adding them.

• Replace raster icons with vector icons (SVGs or React Native Vector Icons).

• Keep only the assets you actually use.

c. Enable Hermes Engine

Hermes is a JavaScript engine built for React Native. It reduces the size of your JavaScript bundle and improves startup time. To enable it, update your android/app/build.gradle:

project.ext.react = [

enableHermes: true

]

Then rebuild your app. You will notice both smaller builds and faster performance on Android.

d. Use Proguard and shrink resources (Android)

Proguard strips out unused Java code, while resource shrinking removes unused images, layouts, and strings. To enable them, add the following in android/app/build.gradle:

minifyEnabled true

shrinkResources true

This ensures only the code and assets you actually need are packaged.

e. Optimize fonts

Including multiple font weights or entire character sets increases app size. Keep only the styles your app requires. If you only use regular and bold, do not include thin, italic, or extra bold.

f. Split APKs or use App Bundles

By default, Android builds contain resources for every device architecture. Splitting APKs or using App Bundles creates smaller builds for each architecture, reducing the download size for end users. In android/app/build.gradle, enable:

splits {

abi {

enable true

reset()

include "armeabi-v7a", "x86", "arm64-v8a", "x86_64"

universalApk false

}

}

Each of these steps contributes a small reduction, but together they can cut your app size significantly and improve the overall user experience.

Testing the Results

After applying optimizations, it is important to verify whether your changes actually reduced the app size. Guesswork won’t help here. You need measurable results.

Start by checking the size of your APK or IPA before and after optimization. On Android, you can simply build the APK and check the file size. For iOS, you can inspect the archived build in Xcode. This gives you a direct comparison.

Go beyond just file size. Install the app on a real device and observe its performance. A lighter app should load faster, install quicker, and in some cases even consume less memory during runtime. Tools like Android Studio Profiler or Xcode Instruments can help you measure these aspects in detail.

It is also a good idea to test across multiple devices. What feels fine on a high-end phone may still be heavy for users with entry-level devices. By testing widely, you can ensure your optimization work benefits the entire audience, not just a subset.

Finally, keep a habit of documenting your results. Maintaining a simple log of changes and their impact on app size will help your team repeat the process with future releases and avoid bloating the app again.

Quick Checklist for Every Build

• Compare APK/IPA size before and after changes

• Test app installation speed on real devices

• Monitor runtime memory usage using profiling tools

• Verify performance on both high-end and entry-level devices

• Log size optimization results for team reference

Conclusion

App size is often overlooked, but it directly affects install rates, performance, and user experience. The good news is that with a few deliberate steps like trimming unused assets, compressing images, cleaning builds, and testing results after every release, you can keep your React Native app lean and efficient.

For teams that want to go beyond quick fixes, working with experienced react native developers can make a big difference. They understand how to balance functionality with performance while ensuring the app remains scalable.

Keeping your app lightweight is not a one-time effort. Treat it as part of your development workflow, and you will consistently deliver faster, smoother apps that users love to install and keep.