Environment Setup

You need Node.js 18+, a code editor (VS Code recommended), and platform SDKs for the devices you target. macOS is required for iOS Simulator; Android emulator runs on Windows, macOS, and Linux.

Prerequisites

You need Node.js 18+, a code editor (VS Code recommended), and platform SDKs for the devices you target. macOS is required for iOS Simulator; Android emulator runs on Windows, macOS, and Linux.

Node.js 18 LTS or 20 LTS — use nvm to manage versions.
Watchman (macOS) — file watcher for Metro: brew install watchman.
Xcode 15+ (macOS only) — iOS Simulator and App Store builds.
Android Studio — SDK, emulator, and platform tools.
JDK 17 — required by modern Android Gradle Plugin.

Create your first project

Using React Native CLI (bare workflow)

npx @react-native-community/cli@latest init MyFirstApp
cd MyFirstApp
# iOS (macOS only)
cd ios && pod install && cd ..
npx react-native run-ios
# Android
npx react-native run-android

Using Expo (recommended for beginners)

npx create-expo-app@latest MyFirstApp
cd MyFirstApp
npx expo start
# Press i for iOS simulator, a for Android emulator

Verify your setup

Metro bundler starts without errors on npx react-native start.
iOS Simulator or Android Emulator launches the default welcome screen.
Edit App.tsx — save — app hot-reloads within 2 seconds.
React Native Doctor: npx react-native doctor — fixes common issues.

Stuck on Android? Enable USB debugging on physical device or create AVD in Android Studio Device Manager.