NetInfo exposes info about online/offline status

NetInfo.fetch().then((reach) => {
  console.log('Initial: ' + reach);
});
function handleFirstConnectivityChange(reach) {
  console.log('First change: ' + reach);
  NetInfo.removeEventListener(
    'change',
    handleFirstConnectivityChange
  );
}
NetInfo.addEventListener(
  'change',
  handleFirstConnectivityChange
);

IOS #

Asynchronously determine if the device is online and on a cellular network.

none - device is offline
wifi - device is online and connected via wifi, or is the iOS simulator
cell - device is connected via Edge, 3G, WiMax, or LTE
unknown - error case and the network status is unknown

Android #

To request network info, you need to add the following line to your app's AndroidManifest.xml:

<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" /> Asynchronously determine if the device is connected and details about that connection.

Android Connectivity Types.

NONE - device is offline
BLUETOOTH - The Bluetooth data connection.
DUMMY - Dummy data connection.
ETHERNET - The Ethernet data connection.
MOBILE - The Mobile data connection.
MOBILE_DUN - A DUN-specific Mobile data connection.
MOBILE_HIPRI - A High Priority Mobile data connection.
MOBILE_MMS - An MMS-specific Mobile data connection.
MOBILE_SUPL - A SUPL-specific Mobile data connection.
VPN - A virtual network using one or more native bearers. Requires API Level 21
WIFI - The WIFI data connection.
WIMAX - The WiMAX data connection.
UNKNOWN - Unknown data connection.

The rest ConnectivityStates are hidden by the Android API, but can be used if necessary.

isConnectionExpensive #

Available on Android. Detect if the current active connection is metered or not. A network is classified as metered when the user is sensitive to heavy data usage on that connection due to monetary costs, data limitations or battery/performance issues.

NetInfo.isConnectionExpensive()
.then(isConnectionExpensive => {
  console.log('Connection is ' + (isConnectionExpensive ? 'Expensive' : 'Not Expensive'));
})
.catch(error => {
  console.error(error);
});

isConnected #

Available on all platforms. Asynchronously fetch a boolean to determine internet connectivity.

NetInfo.isConnected.fetch().then(isConnected => {
  console.log('First, is ' + (isConnected ? 'online' : 'offline'));
});
function handleFirstConnectivityChange(isConnected) {
  console.log('Then, is ' + (isConnected ? 'online' : 'offline'));
  NetInfo.isConnected.removeEventListener(
    'change',
    handleFirstConnectivityChange
  );
}
NetInfo.isConnected.addEventListener(
  'change',
  handleFirstConnectivityChange
);

Methods #

static addEventListener(eventName, handler) #

Invokes the listener whenever network status changes. The listener receives one of the connectivity types listed above.

static removeEventListener(eventName, handler) #

Removes the listener for network status changes.

static fetch() #

Returns a promise that resolves with one of the connectivity types listed above.

static isConnectionExpensive() #

Properties #

isConnected: ObjectExpression #

An object with the same methods as above but the listener receives a boolean which represents the internet connectivity. Use this if you are only interested with whether the device has internet connectivity.