Expo

Documentation

Why not Expo?

Expo is kind of like "Rails" and "Create React App" for React Native. If you use Expo CLI to build your app, we try to manage as much of the complexity of building apps for you as we can, so we call this the managed workflow. A developer using the managed workflow doesn't use Xcode or Android Studio, they just write JavaScript code and manage configuration through app.json.
The managed workflow isn't ready to be used for every app yet. There are plenty of cases where its current constraints may not be appropriate for your project. The intention of this document is to outline some of those cases, so that you don't end up building an app with Expo and getting frustrated when you encounter an obstacle that you can't overcome without switching to the bare workflow. We are either planning on or actively working on building solutions to all of the features listed below, and if you think anything is missing, please bring it to our attention by posting to our feature requests board.
If you are using the bare workflow, the following does not apply to you - the tradeoffs associated with that are the same as React Native in general.
  • Many device APIs are supported (check out the "SDK API Reference" in the sidebar), but not all iOS and Android APIs are available yet: need Bluetooth? Sorry, we haven't built support for it yet. WebRTC? Not quite. One of the most frequent requests we get is for In-App Purchases and Apple and Google Pay integration. We haven't built this yet, but it's on the roadmap. We are constantly adding new APIs, so if we don't have something you need now, you can either use ExpoKit or follow our blog to see the release notes for our SDK updates. Feature prioritization isn't strictly based off of popular vote, but it certainly helps us to gauge what is important to users.
  • The SDK doesn't support all types of background code execution (running code when the app is not foregrounded or the device is sleeping). We support background geolocation (including geofencing) and background fetch, but we do not yet support background audio with the operating-system playback controls and you cannot handle push notifications in the background. This is a work in progress.
  • If you need to keep your app size extremely lean, Expo may not be the best choice. The size for an Expo app on iOS is approximately 20mb (download), and Android is about 15mb. This is because Expo includes a bunch of APIs regardless of whether or not you are using them -- this lets you push over the air updates to use new APIs, but comes at the cost of binary size. We will make this customizable in the future, so you can trim down the size of your binaries.
  • If you know that you want to use a particular push notification service (such as OneSignal) instead of Expo's Push Notification service/API, you will need to use the bare workflow.
  • The minimum supported OS versions are Android 5+ and iOS 10+. If you need to support older versions, you will not be able to use the managed workflow.
  • We typically avoid adding native modules to the SDK if they are tied to externally controlled services - we can't add something to the SDK just because a few users need it for their app, we have to think of the broader userbase.
Are we missing something here? Let us know on our forums or on our feature requests board.