What is Expo: get to know the framework that simplifies development with React Native

If you arrived here asking yourself what Expo is, you’re probably entering the world of mobile development with React Native. And if that’s the case, you’re on the right track — but you’ve probably already noticed that setting everything up to run locally, especially with native libraries, can be more complicated than it seems.

That’s exactly where Expo comes in — a set of tools that promises to greatly simplify the process of developing applications with React Native. In this article, you’ll understand exactly what Expo is, how it works, what its advantages and limitations are, and when it’s really worth using in your projects.

What is Expo?

Expo is an open-source platform that makes it easier to develop, build, and deploy mobile applications using React Native, without you needing to manually configure the native environment for Android or iOS.

In short, Expo provides:

• An SDK with ready-to-use APIs for accessing camera, location, sensors, notifications, and more;
• An application (Expo Go) that lets you run your apps directly on your phone by scanning a QR Code;
• Cloud build and deploy tools with EAS (Expo Application Services).

Instead of installing Android Studio, configuring Xcode, dealing with obscure native dependency errors, and wasting hours on setup, with Expo you write your app in JavaScript/TypeScript, run a command, and see it on your phone in seconds.

Why use Expo?

Let’s face it. Developing an app with pure React Native (CLI) requires:

• Configuring Android Studio and/or Xcode
• Installing emulators
• Taking care of native dependency linking
• Managing certificates, provisioning, etc.

With Expo, you can start with:

$ npx create-expo-app meuApp
$ cd meuApp
$ npx expo start

$ npx create-expo-app meuApp
$ cd meuApp
$ npx expo start

And that’s it. Your app is already running on your phone via Expo Go.

Main advantages of Expo

• Zero initial configuration — you start with everything ready;
• Immediate preview — see your app by scanning a QR code;
• Native APIs via JavaScript — camera, location, sensors, etc., without native code;
• OTA (Over-the-Air) updates — send instant updates without going through the stores;
• Cloud builds with EAS — generate APKs, AABs, and iOS builds without needing a Mac.

What are the limitations of Expo?

Of course, not everything is perfect. Expo also has its limitations, especially when it comes to more complex projects or those needing deeper native customizations.

Main disadvantages

• Dependency on the Expo ecosystem — although it’s open source, you depend on Expo’s APIs and update schedule;
• Limitations in using native libraries — if you need a library not included in the Expo SDK, you’ll need to eject to the bare workflow;
• Build size — because it includes many APIs by default, the app size can be somewhat larger;
• Less fine-grained control over native configurations — deeper customizations require exiting the managed workflow.

When to use Expo?

Expo is perfect for many types of projects — and not just for beginners. See some ideal scenarios for use:

• Rapid MVPs and prototypes
• Internal or enterprise applications
• Projects with limited native API scope
• People who don’t have a Mac and want to publish for iOS
• Solo developers or small teams looking for speed and agility

Projects that require very specific libraries, custom native code, or integrations with SDKs outside Expo’s ecosystem are candidates to eject to the React Native CLI.

Expo vs React Native CLI: practical comparison

Conclusion

Now that you understand what Expo is, it’s easier to decide when to use this platform and how it can significantly accelerate app development with React Native.

If you’re looking for agility, simplicity, and less headache with native environments, Expo is probably the best gateway into the mobile world with JavaScript.

💡Want a more advanced tutorial with Expo + Firebase, or how to use EAS to publish your app on the store? Comment below or follow our blog for upcoming posts.

Ícaro Antunes

I am a software developer with extensive experience in the technology industry. I hold a degree in Computer Engineering and specialize in web development and artificial intelligence. Throughout my career, I have worked on innovative projects that integrated machine learning solutions into enterprise applications.

I am passionate about sharing knowledge and write about the latest trends in software development, focusing on best practices and emerging technologies that drive efficiency and innovation in the industry.

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