Edit

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

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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.

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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.

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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.

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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
);