react-native/docs/autogen_NetInfo.md

---
id: netinfo
title: NetInfo
category: APIs
permalink: docs/netinfo.html
---
<div><div><p>NetInfo exposes info about online/offline status</p><div class="prism language-javascript">NetInfo<span class="token punctuation">.</span><span class="token function">fetch</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">then</span><span class="token punctuation">(</span><span class="token punctuation">(</span>reach<span class="token punctuation">)</span> <span class="token operator">=&gt;</span> <span class="token punctuation">{</span>
  console<span class="token punctuation">.</span><span class="token function">log</span><span class="token punctuation">(</span><span class="token string">'Initial: '</span> <span class="token operator">+</span> reach<span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token keyword">function</span> <span class="token function">handleFirstConnectivityChange</span><span class="token punctuation">(</span>reach<span class="token punctuation">)</span> <span class="token punctuation">{</span>
  console<span class="token punctuation">.</span><span class="token function">log</span><span class="token punctuation">(</span><span class="token string">'First change: '</span> <span class="token operator">+</span> reach<span class="token punctuation">)</span><span class="token punctuation">;</span>
  NetInfo<span class="token punctuation">.</span><span class="token function">removeEventListener</span><span class="token punctuation">(</span>
    <span class="token string">'change'</span><span class="token punctuation">,</span>
    handleFirstConnectivityChange
  <span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span>
NetInfo<span class="token punctuation">.</span><span class="token function">addEventListener</span><span class="token punctuation">(</span>
  <span class="token string">'change'</span><span class="token punctuation">,</span>
  handleFirstConnectivityChange
<span class="token punctuation">)</span><span class="token punctuation">;</span></div><h3><a class="anchor" name="ios"></a>IOS <a class="hash-link" href="docs/netinfo.html#ios">#</a></h3><p>Asynchronously determine if the device is online and on a cellular network.</p><ul><li><code>none</code> - device is offline</li><li><code>wifi</code> - device is online and connected via wifi, or is the iOS simulator</li><li><code>cell</code> - device is connected via Edge, 3G, WiMax, or LTE</li><li><code>unknown</code> - error case and the network status is unknown</li></ul><h3><a class="anchor" name="android"></a>Android <a class="hash-link" href="docs/netinfo.html#android">#</a></h3><p>To request network info, you need to add the following line to your
app's <code>AndroidManifest.xml</code>:</p><p><code>&lt;uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" /&gt;</code>
Asynchronously determine if the device is connected and details about that connection.</p><p>Android Connectivity Types.</p><ul><li><code>NONE</code> - device is offline</li><li><code>BLUETOOTH</code> - The Bluetooth data connection.</li><li><code>DUMMY</code> -  Dummy data connection.</li><li><code>ETHERNET</code> - The Ethernet data connection.</li><li><code>MOBILE</code> - The Mobile data connection.</li><li><code>MOBILE_DUN</code> - A DUN-specific Mobile data connection.</li><li><code>MOBILE_HIPRI</code> - A High Priority Mobile data connection.</li><li><code>MOBILE_MMS</code> - An MMS-specific Mobile data connection.</li><li><code>MOBILE_SUPL</code> -  A SUPL-specific Mobile data connection.</li><li><code>VPN</code> -  A virtual network using one or more native bearers. Requires API Level 21</li><li><code>WIFI</code> - The WIFI data connection.</li><li><code>WIMAX</code> -  The WiMAX data connection.</li><li><code>UNKNOWN</code> - Unknown data connection.</li></ul><p>The rest ConnectivityStates are hidden by the Android API, but can be used if necessary.</p><h3><a class="anchor" name="isconnectionexpensive"></a>isConnectionExpensive <a class="hash-link" href="docs/netinfo.html#isconnectionexpensive">#</a></h3><p>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.</p><div class="prism language-javascript">NetInfo<span class="token punctuation">.</span><span class="token function">isConnectionExpensive</span><span class="token punctuation">(</span><span class="token punctuation">)</span>
<span class="token punctuation">.</span><span class="token function">then</span><span class="token punctuation">(</span>isConnectionExpensive <span class="token operator">=&gt;</span> <span class="token punctuation">{</span>
  console<span class="token punctuation">.</span><span class="token function">log</span><span class="token punctuation">(</span><span class="token string">'Connection is '</span> <span class="token operator">+</span> <span class="token punctuation">(</span>isConnectionExpensive <span class="token operator">?</span> <span class="token string">'Expensive'</span> <span class="token punctuation">:</span> <span class="token string">'Not Expensive'</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span><span class="token punctuation">)</span>
<span class="token punctuation">.</span><span class="token keyword">catch</span><span class="token punctuation">(</span>error <span class="token operator">=&gt;</span> <span class="token punctuation">{</span>
  console<span class="token punctuation">.</span><span class="token function">error</span><span class="token punctuation">(</span>error<span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span><span class="token punctuation">)</span><span class="token punctuation">;</span></div><h3><a class="anchor" name="isconnected"></a>isConnected <a class="hash-link" href="docs/netinfo.html#isconnected">#</a></h3><p>Available on all platforms. Asynchronously fetch a boolean to determine
internet connectivity.</p><div class="prism language-javascript">NetInfo<span class="token punctuation">.</span>isConnected<span class="token punctuation">.</span><span class="token function">fetch</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">then</span><span class="token punctuation">(</span>isConnected <span class="token operator">=&gt;</span> <span class="token punctuation">{</span>
  console<span class="token punctuation">.</span><span class="token function">log</span><span class="token punctuation">(</span><span class="token string">'First, is '</span> <span class="token operator">+</span> <span class="token punctuation">(</span>isConnected <span class="token operator">?</span> <span class="token string">'online'</span> <span class="token punctuation">:</span> <span class="token string">'offline'</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token keyword">function</span> <span class="token function">handleFirstConnectivityChange</span><span class="token punctuation">(</span>isConnected<span class="token punctuation">)</span> <span class="token punctuation">{</span>
  console<span class="token punctuation">.</span><span class="token function">log</span><span class="token punctuation">(</span><span class="token string">'Then, is '</span> <span class="token operator">+</span> <span class="token punctuation">(</span>isConnected <span class="token operator">?</span> <span class="token string">'online'</span> <span class="token punctuation">:</span> <span class="token string">'offline'</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
  NetInfo<span class="token punctuation">.</span>isConnected<span class="token punctuation">.</span><span class="token function">removeEventListener</span><span class="token punctuation">(</span>
    <span class="token string">'change'</span><span class="token punctuation">,</span>
    handleFirstConnectivityChange
  <span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span>
NetInfo<span class="token punctuation">.</span>isConnected<span class="token punctuation">.</span><span class="token function">addEventListener</span><span class="token punctuation">(</span>
  <span class="token string">'change'</span><span class="token punctuation">,</span>
  handleFirstConnectivityChange
<span class="token punctuation">)</span><span class="token punctuation">;</span></div></div><span><h3><a class="anchor" name="methods"></a>Methods <a class="hash-link" href="docs/netinfo.html#methods">#</a></h3><div class="props"><div class="prop"><h4 class="methodTitle"><a class="anchor" name="addeventlistener"></a><span class="methodType">static </span>addEventListener<span class="methodType">(eventName, handler)</span> <a class="hash-link" href="docs/netinfo.html#addeventlistener">#</a></h4><div><p>Invokes the listener whenever network status changes.
The listener receives one of the connectivity types listed above.</p></div></div><div class="prop"><h4 class="methodTitle"><a class="anchor" name="removeeventlistener"></a><span class="methodType">static </span>removeEventListener<span class="methodType">(eventName, handler)</span> <a class="hash-link" href="docs/netinfo.html#removeeventlistener">#</a></h4><div><p>Removes the listener for network status changes.</p></div></div><div class="prop"><h4 class="methodTitle"><a class="anchor" name="fetch"></a><span class="methodType">static </span>fetch<span class="methodType">()</span> <a class="hash-link" href="docs/netinfo.html#fetch">#</a></h4><div><p>Returns a promise that resolves with one of the connectivity types listed
above.</p></div></div><div class="prop"><h4 class="methodTitle"><a class="anchor" name="isconnectionexpensive"></a><span class="methodType">static </span>isConnectionExpensive<span class="methodType">()</span> <a class="hash-link" href="docs/netinfo.html#isconnectionexpensive">#</a></h4></div></div></span><span><h3><a class="anchor" name="properties"></a>Properties <a class="hash-link" href="docs/netinfo.html#properties">#</a></h3><div class="props"><div class="prop"><h4 class="propTitle"><a class="anchor" name="isconnected"></a>isConnected<span class="propType">: ObjectExpression</span> <a class="hash-link" href="docs/netinfo.html#isconnected">#</a></h4><div><p>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.</p></div></div></div></span></div>