NetInfo

NetInfo exposes info about online/offline status

NetInfo.getConnectionInfo().then((connectionInfo) => {
  console.log('Initial, type: ' + connectionInfo.type + ', effectiveType: ' + connectionInfo.effectiveType);
});
function handleFirstConnectivityChange(connectionInfo) {
  console.log('First change, type: ' + connectionInfo.type + ', effectiveType: ' + connectionInfo.effectiveType);
  NetInfo.removeEventListener(
    'connectionChange',
    handleFirstConnectivityChange
  );
}
NetInfo.addEventListener(
  'connectionChange',
  handleFirstConnectivityChange
);

ConnectionType enum

ConnectionType describes the type of connection the device is using to communicate with the network.

Cross platform values for ConnectionType:

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

Android-only values for ConnectionType:

• bluetooth - device is connected via Bluetooth
• ethernet - device is connected via Ethernet
• wimax - device is connected via WiMAX

EffectiveConnectionType enum

Cross platform values for EffectiveConnectionType:

• 2g
• 3g
• 4g
• 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" />

Methods

• addEventListener
• removeEventListener
• getConnectionInfo
• isConnectionExpensive

Properties

• isConnected

Reference

Methods

addEventListener()

NetInfo.addEventListener(eventName, handler);

Adds an event handler.

Parameters:

Name	Type	Required	Description
eventName	enum(connectionChange, change)	Yes	The change event name.
handler	function	Yes	Listener function.

Supported events:

• connectionChange: Fires when the network status changes. The argument to the event handler is an object with keys:
  • type: A ConnectionType (listed above)
  • effectiveType: An EffectiveConnectionType (listed above)
• change: This event is deprecated. Listen to connectionChange instead. Fires when the network status changes. The argument to the event handler is one of the deprecated connectivity types listed above.

removeEventListener()

NetInfo.removeEventListener(eventName, handler);

Removes the listener for network status changes.

Parameters:

Name	Type	Required	Description
eventName	enum(connectionChange, change)	Yes	The change event name.
handler	function	Yes	Listener function.

getConnectionInfo()

NetInfo.getConnectionInfo();

Returns a promise that resolves to an object with type and effectiveType keys whose values are a ConnectionType and an EffectiveConnectionType), respectively.

isConnectionExpensive()

NetInfo.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);
});

Properties

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(
    'connectionChange',
    handleFirstConnectivityChange
  );
}
NetInfo.isConnected.addEventListener(
  'connectionChange',
  handleFirstConnectivityChange
);