EAS Build or Local Build: Which One Should You Use to Ship Your App?

If you want to ship your Expo app, EAS Build is generally the better choice over local builds. EAS Build automates the entire build process and optimizes for both Android and iOS, allowing you to focus on development rather than environment setup.

What is EAS Build?

EAS Build is Expo's cloud-based build service designed to simplify and streamline the process of generating binaries for iOS and Android. It manages dependencies, platform-specific configurations, and handles both the build infrastructure and the complexity of native modules. This service takes the burden off your local machine and provides a consistent environment for builds.

How Does EAS Build Compare to Local Builds?

EAS Build offers convenience and reliability, while local builds give you more control over the build environment. However, using EAS Build means you don’t have to worry about managing the native tooling required for iOS and Android especially when it comes to resolving dependencies and configuring environments.

What are the Advantages of EAS Build?

1. Simplicity: With EAS Build you can create a build command with just a few configurations.
2. Environment Consistency: Since the builds run in the cloud, they are not affected by local machine configurations.
3. Automatic Updates: EAS manages updates to tools and dependencies, ensuring you are using supported versions.
4. Fast Builds: The cloud infrastructure is generally faster than local hardware, especially for larger projects.

What are the Benefits of Local Builds?

1. Full Control: You can tweak every aspect of the build process, which is vital for complex applications.
2. No Network Requirement: You don’t need to rely on internet connectivity, which can be a plus when working in restricted environments.
3. Feature Testing Before Submission: Local builds allow for immediate iterations without waiting for cloud processing time.

When Should I Use EAS Build?

If you prefer a fully managed service or you are new to mobile development, EAS Build is the ideal choice. It reduces setup time and complexity and is suitable for most projects, especially those using Expo’s managed workflow.

When Should I Use Local Builds?

Opt for local builds when your app has heavy customization needs or requires specific native modules that are difficult to configure in EAS. It is also the preferred choice for developers familiar with the intricacies of native code, especially if they are required to maintain constant modification and testing cycles.

Can EAS Build Handle Native Modules?

Yes, EAS Build can handle native modules; however, you must ensure they are properly configured in your project. You will need to define these in the project's eas.json configuration file under the relevant build profiles. If you encounter issues, verify that the native dependencies are compatible with the latest versions of Expo SDK.

What Build Profiles Should I Have in EAS Build?

Typical build profiles in eas.json may include:

1. production: For release-ready builds with optimizations enabled.
2. development: Good for debugging, including detailed logs and slower compilation speeds.
3. preview: Useful for testing features before deploying them in production.

How Do I Set Up Build Profiles in EAS?

Here's how you can quickly set up build profiles:

1. At the root of your Expo project, open or create eas.json.
2. Add your needed profiles. For example:

{
  "build": {
    "production": {
      "releaseChannel": "default"
    },
    "development": {
      "releaseChannel": "development"
    }
  }
}

3. Save your file and you can specify which profile to use during your build command.

What Can I Ship Over The Air (OTA) with EAS?

With EAS, you can ship OTA updates for JavaScript code and assets, but not for native code changes. This means that if you need to update React Native or any native modules, you will still have to do a complete rebuild and resubmit the app to the stores.

How to Build an Expo App for App Store?

To build your Expo app for the App Store:

1. Ensure you're using the EAS CLI: npm install -g eas-cli
2. Setup your app.json configuration accordingly, specifying the bundle identifier and necessary metadata for iOS.
3. Run eas build --platform ios and follow the prompts, then submit your binary through App Store Connect once the build completes.

How Do EAS Updates Compare to Local Builds?

EAS Updates allows for quick iterations on JavaScript and assets but won’t cover native changes, which require going through the full build process again. A local build can reflect all changes, be they JavaScript or native, making local builds essential for comprehensive testing before release.

Can I Hybridize My Workflow Between EAS and Local Builds?

Yes, many teams employ a hybrid approach, utilizing EAS for testing and production releases, while employing local builds for development or when testing new native modules. This allows for flexibility and faster testing while maintaining control over critical configurations as needed.

Conclusion

To ship your Expo app efficiently, choose EAS Build for cloud convenience and automated builds, especially if your project benefits from Expo's managed services. If you need complete control over the environment and setup, local builds may be the better option. Understanding both options allows for optimal decisions based on project requirements.