How do I connect to a specific Wi-Fi network in Android programmatically?

The earlier answer works, but the solution can actually be simpler. Looping through the configured networks list is not required as you get the network id when you add the network through the WifiManager.

So the complete, simplified solution would look something like this:

WifiConfiguration wifiConfig = new WifiConfiguration();
wifiConfig.SSID = String.format("\"%s\"", ssid);
wifiConfig.preSharedKey = String.format("\"%s\"", key);

WifiManager wifiManager = (WifiManager)getSystemService(WIFI_SERVICE);
//remember id
int netId = wifiManager.addNetwork(wifiConfig);
wifiManager.disconnect();
wifiManager.enableNetwork(netId, true);
wifiManager.reconnect();

You need to create WifiConfiguration instance like this:

String networkSSID = "test";
String networkPass = "pass";

WifiConfiguration conf = new WifiConfiguration();
conf.SSID = "\"" + networkSSID + "\"";   // Please note the quotes. String should contain ssid in quotes

Then, for WEP network you need to do this:

conf.wepKeys[0] = "\"" + networkPass + "\""; 
conf.wepTxKeyIndex = 0;
conf.allowedKeyManagement.set(WifiConfiguration.KeyMgmt.NONE);
conf.allowedGroupCiphers.set(WifiConfiguration.GroupCipher.WEP40); 

For WPA network you need to add passphrase like this:

conf.preSharedKey = "\""+ networkPass +"\"";

For Open network you need to do this:

conf.allowedKeyManagement.set(WifiConfiguration.KeyMgmt.NONE);

Then, you need to add it to Android wifi manager settings:

WifiManager wifiManager = (WifiManager)context.getSystemService(Context.WIFI_SERVICE); 
wifiManager.addNetwork(conf);

And finally, you might need to enable it, so Android connects to it:

List<WifiConfiguration> list = wifiManager.getConfiguredNetworks();
for( WifiConfiguration i : list ) {
    if(i.SSID != null && i.SSID.equals("\"" + networkSSID + "\"")) {
         wifiManager.disconnect();
         wifiManager.enableNetwork(i.networkId, true);
         wifiManager.reconnect();               

         break;
    }           
 }

UPD: In case of WEP, if your password is in hex, you do not need to surround it with quotes.


Before connecting WIFI network you need to check security type of the WIFI network ScanResult class has a capabilities. This field gives you type of network

Refer: https://developer.android.com/reference/android/net/wifi/ScanResult.html#capabilities

There are three types of WIFI networks.

First, instantiate a WifiConfiguration object and fill in the network’s SSID (note that it has to be enclosed in double quotes), set the initial state to disabled, and specify the network’s priority (numbers around 40 seem to work well).

WifiConfiguration wfc = new WifiConfiguration();

wfc.SSID = "\"".concat(ssid).concat("\"");
wfc.status = WifiConfiguration.Status.DISABLED;
wfc.priority = 40;

Now for the more complicated part: we need to fill several members of WifiConfiguration to specify the network’s security mode. For open networks.

wfc.allowedKeyManagement.set(WifiConfiguration.KeyMgmt.NONE);
wfc.allowedProtocols.set(WifiConfiguration.Protocol.RSN);
wfc.allowedProtocols.set(WifiConfiguration.Protocol.WPA);
wfc.allowedAuthAlgorithms.clear();
wfc.allowedPairwiseCiphers.set(WifiConfiguration.PairwiseCipher.CCMP);
wfc.allowedPairwiseCiphers.set(WifiConfiguration.PairwiseCipher.TKIP);
wfc.allowedGroupCiphers.set(WifiConfiguration.GroupCipher.WEP40);
wfc.allowedGroupCiphers.set(WifiConfiguration.GroupCipher.WEP104);
wfc.allowedGroupCiphers.set(WifiConfiguration.GroupCipher.CCMP);
wfc.allowedGroupCiphers.set(WifiConfiguration.GroupCipher.TKIP);

For networks using WEP; note that the WEP key is also enclosed in double quotes.

wfc.allowedKeyManagement.set(WifiConfiguration.KeyMgmt.NONE);
wfc.allowedProtocols.set(WifiConfiguration.Protocol.RSN);
wfc.allowedProtocols.set(WifiConfiguration.Protocol.WPA);
wfc.allowedAuthAlgorithms.set(WifiConfiguration.AuthAlgorithm.OPEN);
wfc.allowedAuthAlgorithms.set(WifiConfiguration.AuthAlgorithm.SHARED);
wfc.allowedPairwiseCiphers.set(WifiConfiguration.PairwiseCipher.CCMP);
wfc.allowedPairwiseCiphers.set(WifiConfiguration.PairwiseCipher.TKIP);
wfc.allowedGroupCiphers.set(WifiConfiguration.GroupCipher.WEP40);
wfc.allowedGroupCiphers.set(WifiConfiguration.GroupCipher.WEP104);

if (isHexString(password)) wfc.wepKeys[0] = password;
else wfc.wepKeys[0] = "\"".concat(password).concat("\"");
wfc.wepTxKeyIndex = 0;

For networks using WPA and WPA2, we can set the same values for either.

wfc.allowedProtocols.set(WifiConfiguration.Protocol.RSN);
wfc.allowedProtocols.set(WifiConfiguration.Protocol.WPA);
wfc.allowedKeyManagement.set(WifiConfiguration.KeyMgmt.WPA_PSK);
wfc.allowedPairwiseCiphers.set(WifiConfiguration.PairwiseCipher.CCMP);
wfc.allowedPairwiseCiphers.set(WifiConfiguration.PairwiseCipher.TKIP);
wfc.allowedGroupCiphers.set(WifiConfiguration.GroupCipher.WEP40);
wfc.allowedGroupCiphers.set(WifiConfiguration.GroupCipher.WEP104);
wfc.allowedGroupCiphers.set(WifiConfiguration.GroupCipher.CCMP);
wfc.allowedGroupCiphers.set(WifiConfiguration.GroupCipher.TKIP);

wfc.preSharedKey = "\"".concat(password).concat("\"");

Finally, we can add the network to the WifiManager’s known list

WifiManager wfMgr = (WifiManager) context.getSystemService(Context.WIFI_SERVICE);
int networkId = wfMgr.addNetwork(wfc);
if (networkId != -1) {
 // success, can call wfMgr.enableNetwork(networkId, true) to connect
} 

Credit to @raji-ramamoorthi & @kenota

The solution which worked for me is combination of above contributors in this thread.

To get ScanResult here is the process.

WifiManager wifi = (WifiManager) getSystemService(Context.WIFI_SERVICE);
if (wifi.isWifiEnabled() == false) {
            Toast.makeText(getApplicationContext(), "wifi is disabled..making it enabled", Toast.LENGTH_LONG).show();
            wifi.setWifiEnabled(true);
        }

BroadcastReceiver broadcastReceiver = new BroadcastReceiver() {
            @Override
            public void onReceive(Context c, Intent intent) {
                 wifi.getScanResults();
            }
        };

Notice to unregister it on onPause & onStop live this unregisterReceiver(broadcastReceiver);

public void connectWiFi(ScanResult scanResult) {
        try {

            Log.v("rht", "Item clicked, SSID " + scanResult.SSID + " Security : " + scanResult.capabilities);

            String networkSSID = scanResult.SSID;
            String networkPass = "12345678";

            WifiConfiguration conf = new WifiConfiguration();
            conf.SSID = "\"" + networkSSID + "\"";   // Please note the quotes. String should contain ssid in quotes
            conf.status = WifiConfiguration.Status.ENABLED;
            conf.priority = 40;

            if (scanResult.capabilities.toUpperCase().contains("WEP")) {
                Log.v("rht", "Configuring WEP");    
                conf.allowedKeyManagement.set(WifiConfiguration.KeyMgmt.NONE);
                conf.allowedProtocols.set(WifiConfiguration.Protocol.RSN);
                conf.allowedProtocols.set(WifiConfiguration.Protocol.WPA);
                conf.allowedAuthAlgorithms.set(WifiConfiguration.AuthAlgorithm.OPEN);
                conf.allowedAuthAlgorithms.set(WifiConfiguration.AuthAlgorithm.SHARED);
                conf.allowedPairwiseCiphers.set(WifiConfiguration.PairwiseCipher.CCMP);
                conf.allowedPairwiseCiphers.set(WifiConfiguration.PairwiseCipher.TKIP);
                conf.allowedGroupCiphers.set(WifiConfiguration.GroupCipher.WEP40);
                conf.allowedGroupCiphers.set(WifiConfiguration.GroupCipher.WEP104);

                if (networkPass.matches("^[0-9a-fA-F]+$")) {
                    conf.wepKeys[0] = networkPass;
                } else {
                    conf.wepKeys[0] = "\"".concat(networkPass).concat("\"");
                }

                conf.wepTxKeyIndex = 0;

            } else if (scanResult.capabilities.toUpperCase().contains("WPA")) {
                Log.v("rht", "Configuring WPA");

                conf.allowedProtocols.set(WifiConfiguration.Protocol.RSN);
                conf.allowedProtocols.set(WifiConfiguration.Protocol.WPA);
                conf.allowedKeyManagement.set(WifiConfiguration.KeyMgmt.WPA_PSK);
                conf.allowedPairwiseCiphers.set(WifiConfiguration.PairwiseCipher.CCMP);
                conf.allowedPairwiseCiphers.set(WifiConfiguration.PairwiseCipher.TKIP);
                conf.allowedGroupCiphers.set(WifiConfiguration.GroupCipher.WEP40);
                conf.allowedGroupCiphers.set(WifiConfiguration.GroupCipher.WEP104);
                conf.allowedGroupCiphers.set(WifiConfiguration.GroupCipher.CCMP);
                conf.allowedGroupCiphers.set(WifiConfiguration.GroupCipher.TKIP);

                conf.preSharedKey = "\"" + networkPass + "\"";

            } else {
                Log.v("rht", "Configuring OPEN network");
                conf.allowedKeyManagement.set(WifiConfiguration.KeyMgmt.NONE);
                conf.allowedProtocols.set(WifiConfiguration.Protocol.RSN);
                conf.allowedProtocols.set(WifiConfiguration.Protocol.WPA);
                conf.allowedAuthAlgorithms.clear();
                conf.allowedPairwiseCiphers.set(WifiConfiguration.PairwiseCipher.CCMP);
                conf.allowedPairwiseCiphers.set(WifiConfiguration.PairwiseCipher.TKIP);
                conf.allowedGroupCiphers.set(WifiConfiguration.GroupCipher.WEP40);
                conf.allowedGroupCiphers.set(WifiConfiguration.GroupCipher.WEP104);
                conf.allowedGroupCiphers.set(WifiConfiguration.GroupCipher.CCMP);
                conf.allowedGroupCiphers.set(WifiConfiguration.GroupCipher.TKIP);
            }

            WifiManager wifiManager = (WifiManager) WiFiApplicationCore.getAppContext().getSystemService(Context.WIFI_SERVICE);
            int networkId = wifiManager.addNetwork(conf);

            Log.v("rht", "Add result " + networkId);

            List<WifiConfiguration> list = wifiManager.getConfiguredNetworks();
            for (WifiConfiguration i : list) {
                if (i.SSID != null && i.SSID.equals("\"" + networkSSID + "\"")) {
                    Log.v("rht", "WifiConfiguration SSID " + i.SSID);

                    boolean isDisconnected = wifiManager.disconnect();
                    Log.v("rht", "isDisconnected : " + isDisconnected);

                    boolean isEnabled = wifiManager.enableNetwork(i.networkId, true);
                    Log.v("rht", "isEnabled : " + isEnabled);

                    boolean isReconnected = wifiManager.reconnect();
                    Log.v("rht", "isReconnected : " + isReconnected);

                    break;
                }
            }

        } catch (Exception e) {
            e.printStackTrace();
        }
    }