使用CRNA创建独立App：为何两种方式生成的APK大小差异巨大？

Great question—this is a common point of confusion when working with Expo and React Native. Let’s break down the key reasons the Expo build results in a 26MB APK while your manual ejected build is only 7MB:

• Universal Compatibility Over Minimalism
  Expo’s exp build creates a "universal" APK that supports nearly all Android devices and includes every native module Expo offers (think camera, location, push notifications, etc.)—even if your app never uses them. This broad compatibility ensures your app works out of the box for most users, but it adds significant bloat. When you eject and build manually, you only include the exact dependencies your app needs, cutting out all unused code.

• Prebuilt Frameworks and OTA Infrastructure
  Expo’s build pipeline uses precompiled native frameworks optimized for stability and Expo’s over-the-air (OTA) update system. The OTA support lets you push app updates without going through Google Play, but it requires extra code bundled into the APK to handle download, verification, and installation of updates. Manual builds don’t include this OTA layer unless you explicitly set it up, saving valuable space.

• Less Aggressive Optimization by Default
  When you build manually, you can leverage tools like ProGuard/R8 to minify, obfuscate, and strip unused code from both Java/Kotlin and JavaScript parts of your app. Expo’s build process does apply some optimizations, but it prioritizes ease of use and compatibility over maximum size reduction. It also keeps more fallback resources and supports multiple CPU architectures (like armv7, arm64, x86) by default, whereas you might target only the most common architectures in a manual build.

• Default Asset Bundling
  Expo includes a set of default assets (like system fonts, fallback icons, and compatibility resources) to ensure consistent behavior across devices. When you eject, you have full control over which assets are included—you can delete unused fonts, compress images more aggressively, and remove any resources your app doesn’t depend on, further trimming the APK size.

In short, Expo’s build is designed to make app development fast and hassle-free with broad compatibility, while manual ejected builds let you optimize every aspect for minimal size at the cost of more setup and maintenance.

内容的提问来源于stack exchange，提问作者Pavlo Kyrylenko