React Native  

How to Set Up React Expo and Run Your First App: A Complete Guide

React Native has become one of the most popular frameworks for building cross-platform mobile apps. But if you’re just starting out, the easiest path is to use Expo, a powerful toolchain that simplifies development, testing, and deployment.

In this article, you’ll learn:

  • What Expo is

  • How to install Expo and set up your environment

  • How to create your first React Native (Expo) app

  • How to run the app on your device or emulator

  • Useful tips for beginners

Let’s get started!

What Is Expo?

Expo is a framework and a platform for universal React applications. It provides:

  • A managed workflow (no need for Android Studio/Xcode initially)

  • A CLI for developing and running apps

  • Expo Go, a mobile app for instantly previewing your project

  • Access to pre-built native modules

In short: Expo makes mobile app development faster, easier, and beginner-friendly.

1. Install Node.js

Expo requires Node.js and npm (or Yarn).

Download and install Node.js from the official website:

➡️ https://nodejs.org

To verify installation, run:

node -v
npm -v

2. Install Expo CLI

Expo has transitioned to a new tool called Expo CLI using the expo command.

Install it globally:

npm install -g expo-cli

Or use the newer recommended approach without global install:

npx create-expo-app

3. Create a New Expo Project

Run:

npx create-expo-app my-first-app

Move into your project folder:

cd my-first-app

Inside, you will find:

  • App.js — the main entry file

  • package.json — dependencies

  • Assets folder for images and fonts

4. Start the Development Server

Start Expo:

npx expo start

This opens Expo DevTools in your browser and prints a QR code in the terminal.

5. Run the App

Option A: Use Your Physical Device (Easiest)

  1. Install Expo Go from Google Play or the App Store.

  2. Open Expo Go.

  3. Scan the QR code from your terminal or DevTools.

Your app will instantly appear and reload automatically when you save changes.

Option B: Use an Android Emulator

  1. Install Android Studio

  2. Open AVD Manager

  3. Create and start a virtual device

  4. Run:

npx expo start --android

Expo will launch the app directly on the emulator.

Option C: Use an iOS Simulator (macOS only)

Requires Xcode.

Run:

npx expo start --ios

6. Edit Your App

Open App.js and change the code:

export default function App() {
  return (
    <View style={{ flex: 1, justifyContent: 'center', alignItems: 'center' }}>
      <Text>Hello from my first Expo app!</Text>
    </View>
  );
}

Save the file — your app reloads instantly!

7. Build a Standalone App (Optional)

Expo can build your Android or iOS app:

npx expo prebuild
npx expo build:android
npx expo build:ios

Or use the Expo online build service (EAS):

npx eas build

Final Tips for Beginners

  • Use Expo Go for fast development

  • Learn basic React first — Expo is just the toolchain

  • Install VS Code and the ES7+ React/Redux snippets extension

  • Use Expo’s documentation — it’s beginner-friendly

  • Explore Expo SDK modules: camera, sensors, notifications, maps, etc.

Conclusion

Setting up React Native with Expo is quick and painless. With just a few commands, you can create and run a mobile app on your device or emulator—no native setup required.

Expo is ideal for beginners, rapid prototyping, and launching production apps without dealing with native code.

Start experimenting, edit components, and watch your app come alive!

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