Expo (opens in a new tab) is a framework and a set of tools built around React Native that simplifies the process of developing, testing, and deploying React Native applications. Expo aims to streamline various aspects of the development workflow, making it more accessible for developers, especially those who are new to mobile app development or who prioritize rapid development.

Here are key aspects of Expo and reasons why developers might choose to use it over the React Native CLI:

1. Quick Start and Development:

• Expo provides a quick and easy way to get started with React Native development. Developers can create a new Expo project with just one command (expo init) and start building their app without the need for complex configurations.

2. Development Environment:

• Expo includes a development environment that runs on your local machine and allows you to preview your app on a physical device using the Expo Go app. This eliminates the need for setting up Android Studio or Xcode for basic development.

3. Expo Client App:

• The Expo Client app (Expo Go) allows developers to test their React Native applications on physical devices without the need for complex build processes. Developers can scan a QR code, and the app will be loaded on their device instantly.

4. Managed Workflow:

• Expo offers a "managed" workflow that abstracts away the native build process. This allows developers to focus on writing JavaScript code and utilizing Expo APIs without dealing directly with native code, which can be a significant advantage for those less familiar with native development.

5. Built-in APIs and Modules:

• Expo comes with a wide range of pre-built native modules and APIs that cover common functionalities such as camera access, geolocation, push notifications, and more. These can be easily integrated into Expo projects without the need for native modules.

6. Over-the-Air (OTA) Updates:

• Expo provides Over-the-Air (OTA) updates, allowing developers to push updates to their apps without requiring users to download a new version from an app store. This can be useful for rapidly deploying bug fixes or new features.

7. Expo SDK:

• The Expo SDK is a set of JavaScript libraries and native modules that Expo applications use. It includes APIs for accessing device features and services. Developers can update the Expo SDK version in their projects without dealing with native module upgrades.

8. Easier Deployment:

• Expo simplifies the deployment process. Expo handles the build and packaging of the app for both iOS and Android, and developers can use the Expo CLI or web-based tools to build standalone binaries for app stores.

9. Community and Documentation:

• Expo has a vibrant and supportive community. Its documentation is extensive and beginner-friendly, making it easier for developers to find answers to their questions and get started quickly.

When to Choose Expo vs. React Native CLI:

• Choose Expo If:

  • You are a beginner or want a quick start with React Native.
  • You prioritize ease of development and don't need advanced native modules.
  • You want to test your app on physical devices without dealing with native build tools.
  • You are building a relatively simple app and don't need deep customization.

• Choose React Native CLI If:

  • You require extensive customization or need to interact with native modules not supported by Expo.
  • You have specific native dependencies that are not compatible with Expo.
  • You are comfortable setting up and working with Android Studio and Xcode.
  • You need more control over the native build process.

In summary, Expo is a powerful and convenient option for many developers, especially those looking for a streamlined and beginner-friendly experience. However, developers with specific requirements or who need extensive customization may opt for the React Native CLI to have more control over the development process.