Expo vs Flutter: What are the differences?

Expo and Flutter are both popular frameworks used for developing cross-platform mobile applications. While they serve a similar purpose, there are key differences between the two.

1. Language and Development Environment: Expo uses JavaScript and React Native, making it suitable for developers already familiar with these technologies. On the other hand, Flutter uses Dart, a language specifically designed for the framework. Flutter also has its own set of development tools, like the Flutter SDK and Dart compiler.

2. UI Components and Customization: Expo provides a wide range of pre-built UI components, allowing developers to quickly create screens and user interfaces. However, the customization options might be limited compared to Flutter. Flutter, being a UI framework, offers a powerful set of widgets and allows for more extensive customization, enabling developers to build complex and visually appealing interfaces.

3. Access to Native APIs: Expo abstracts many native APIs and provides a simplified interface for accessing them. This approach helps speed up development and simplifies the learning curve for beginners. In contrast, Flutter provides direct access to native APIs, allowing developers to leverage the full capabilities of the underlying platform. This can be advantageous for projects requiring in-depth native integration.

4. Performance and Rendering: Flutter uses its own rendering engine, Skia, which allows for highly performant and smooth animations. It also uses a "write once, run anywhere" approach, enabling applications to have consistent performance across different platforms. Expo, while still performant, relies on the underlying React Native framework, which can sometimes introduce minor performance limitations.

5. Third-Party Library Support: Expo has a vast ecosystem of community-maintained libraries and modules. It simplifies the process of integrating third-party libraries, as most modules work out of the box with Expo. Flutter, on the other hand, has a rapidly growing ecosystem with a wide range of libraries and packages available. However, integrating some of these libraries may require additional configuration and might not always be plug-and-play.

6. Publishing and Distribution: Expo provides a managed workflow, enabling developers to easily build, publish, and distribute their applications over the air. This approach simplifies the process and removes the need for complex code signing and manual app updates. Flutter, although it provides tools for building and packaging applications, requires developers to handle app signing and distribution manually, which might involve more steps and a steeper learning curve.

In summary, Expo, built on React Native, offers a simplified and beginner-friendly way to develop cross-platform applications with a wide range of pre-built UI components. On the other hand, Flutter, using Dart, provides an extensive customization and performance-focused approach, with direct access to native APIs, making it a powerful option for building visually stunning and performant applications.