React Native Bundle Size

Instructions

A smaller bundle parses faster and starts faster. Target the JS bundle first -- native code changes are a distant second.

1. Hermes Bytecode

Hermes compiles JS to bytecode at build time, cutting parse cost and reducing app size.

• android/gradle.properties: hermesEnabled=true
• ios/Podfile: :hermes_enabled => true (default in modern templates)

Verify at runtime:

export const isHermes = !!(globalThis as { HermesInternal?: unknown }).HermesInternal;