Question: The documentation says it should be used instead of LocalStorage, but it doesn't list anything regarding how large it is. If I recall, LocalStorage in web browsers is only about 10mb.

<https://facebook.github.io/react-native/docs/asyncstorage.html>

Answer: 
The new way of increasing AsyncStorage size on react-native is to add `AsyncStorage_db_size_in_MB=` property to your `android/gradle.properties` as shown here: <https://react-native-async-storage.github.io/async-storage/docs/advanced/db_size/>
On Android the limit is 6mb by default. Check [this](https://github.com/facebook/react-native/blob/master/ReactAndroid/src/main/java/com/facebook/react/modules/storage/ReactDatabaseSupplier.java#L46). 

But you can increase that limit calling the method [setMaximumSize](https://github.com/facebook/react-native/blob/master/ReactAndroid/src/main/java/com/facebook/react/modules/storage/ReactDatabaseSupplier.java#L142).