Expo

Overview

Expo is an open-source framework and platform designed to simplify the development, deployment, and iteration of universal React Native applications. It provides a comprehensive set of tools and services that abstract away many of the complexities associated with native mobile development, enabling JavaScript and TypeScript developers to build applications for iOS, Android, and web from a single codebase Expo Web Documentation. The platform manages native build configurations and provides access to device capabilities through a unified JavaScript API, the Expo SDK.

The core of Expo's offering includes the Expo SDK, which exposes common native APIs like camera, location, and notifications through JavaScript Expo SDK Overview. This allows developers to focus on application logic without directly interacting with Objective-C, Swift, Java, or Kotlin. For development, Expo Go is a client application that enables rapid iteration by running projects directly on physical devices or simulators without requiring Xcode or Android Studio installations. This facilitates quick testing and debugging during the development cycle.

Beyond development, Expo provides cloud-based services under the umbrella of Expo Application Services (EAS). EAS Build automates the process of generating app binaries (.ipa for iOS, .apk or .aab for Android) without requiring local native build environments EAS Build Introduction. EAS Update facilitates over-the-air (OTA) updates, allowing developers to deploy code and asset changes to their applications instantly, bypassing traditional app store review processes for non-native changes EAS Update Introduction. EAS Submit streamlines the submission of app binaries to the Apple App Store and Google Play Store.

Expo is particularly well-suited for rapid prototyping and projects where a single codebase across multiple platforms is a priority. Its managed workflow is ideal for developers familiar with JavaScript and React who want to enter mobile development without deep native expertise. While it offers a managed environment, Expo also supports a bare workflow, allowing developers to eject from the managed environment to gain full control over native code when specific custom native modules are required Managed vs. Bare Workflow. This flexibility makes Expo a viable option for a range of projects, from simple utility apps to more complex applications requiring custom native integrations.

Key features

• Expo SDK: A collection of JavaScript modules that provide access to device capabilities and APIs, abstracting native code complexities Expo SDK Reference.
• Expo Go: A development client that allows running and testing Expo projects on iOS and Android devices or simulators without building native app binaries locally Expo Go Guide.
• EAS Build: Cloud-based service for building universal application binaries (.ipa and .aab) for iOS and Android, eliminating the need for local native build environments EAS Build Documentation.
• EAS Update: Enables over-the-air (OTA) updates for JavaScript code and assets, allowing instant deployment of changes to users without full app store submissions EAS Update Documentation.
• EAS Submit: A service to automate the submission of app binaries to the Apple App Store and Google Play Store.
• Managed Workflow: A streamlined development environment where Expo handles native configuration, dependencies, and build processes Expo Workflows Explained.
• Bare Workflow: Provides full control over the native project, allowing for the integration of custom native modules and libraries not included in the Expo SDK.
• Expo Router: A file-system based router for universal React Native applications, supporting web, iOS, and Android navigation from a single codebase Expo Router Introduction.

Pricing

The following table outlines Expo's pricing tiers as of April 26, 2026. For the most current pricing details, refer to the official Expo pricing page.

Common integrations

• React Native: Expo is built on top of React Native, leveraging its component model and ecosystem React Native Getting Started.
• Firebase: Integration with Google's Firebase services for backend functionality like authentication, databases, and cloud functions Firebase Documentation.
• Stripe: Payment processing integration for in-app purchases and subscriptions Expo Stripe SDK.
• Sentry: Error tracking and performance monitoring for React Native applications Expo Sentry Documentation.
• Push Notifications: Integration with native push notification services (Apple Push Notification Service, Firebase Cloud Messaging) via Expo's Notifications API Expo Notifications Documentation.

Alternatives

• React Native: The underlying framework Expo is built upon, offering more direct control over native modules at the cost of increased setup complexity React Native Official Site.
• Flutter: A UI toolkit developed by Google for building natively compiled applications for mobile, web, and desktop from a single codebase using Dart Flutter Official Site.
• Ionic: An open-source UI toolkit for building high-quality, cross-platform mobile and desktop apps using web technologies like HTML, CSS, and JavaScript, often combined with frameworks like Angular, React, or Vue.js.

Getting started

To begin developing with Expo, you typically install the Expo CLI and then create a new project. The following steps demonstrate a basic setup to create and run a new Expo application:

# Install the Expo CLI globally
npm install -g expo-cli

# Create a new Expo project
expo init MyFirstExpoApp

# Navigate into your new project directory
cd MyFirstExpoApp

# Start the development server
expo start

After running expo start, a development server will launch, and a QR code will be displayed in your terminal. You can then scan this QR code using the Expo Go app on your physical device or open the app in an iOS simulator or Android emulator. The core application code resides in App.js (or App.tsx for TypeScript projects) and can be modified to display content:

// App.js
import React from 'react';
import { StyleSheet, Text, View } from 'react-native';

export default function App() {
  return (
    <View style={styles.container}>
      <Text>Hello, appfield!</Text>
    </View>
  );
}

const styles = StyleSheet.create({
  container: {
    flex: 1,
    backgroundColor: '#fff',
    alignItems: 'center',
    justifyContent: 'center',
  },
});