How to Check the Internet Connection in Android

Android check internet connection

This method checks whether mobile is connected to internet and returns true if connected:

private boolean isNetworkConnected() {
    ConnectivityManager cm = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);

    return cm.getActiveNetworkInfo() != null && cm.getActiveNetworkInfo().isConnected();
}

in manifest,

<uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />

Edit:
This method actually checks if device is connected to internet(There is a possibility it's connected to a network but not to internet).

public boolean isInternetAvailable() {
    try {
        InetAddress ipAddr = InetAddress.getByName("google.com"); 
        //You can replace it with your name
            return !ipAddr.equals("");

        } catch (Exception e) {
            return false;
    }
}

How to check currently internet connection is available or not in android

This will tell if you're connected to a network:

boolean connected = false;
ConnectivityManager connectivityManager = (ConnectivityManager)getSystemService(Context.CONNECTIVITY_SERVICE);
    if(connectivityManager.getNetworkInfo(ConnectivityManager.TYPE_MOBILE).getState() == NetworkInfo.State.CONNECTED || 
            connectivityManager.getNetworkInfo(ConnectivityManager.TYPE_WIFI).getState() == NetworkInfo.State.CONNECTED) {
        //we are connected to a network
        connected = true;
    }
    else
        connected = false;

Warning: If you are connected to a WiFi network that doesn't include internet access or requires browser-based authentication, connected will still be true.

You will need this permission in your manifest:

<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />

How to test for active internet connection in android

Follow below code to check properly Internet is available or not as well as active or not.

   //I have taken dummy icon from server, so it may be removed in future. So you can place one small icon on server and then access your own URL.

1. Specify Permission in manifest file, also make sure for marshmellwo runtime permission handle. As I am not going to show reuntime permission here.

    <uses-permission android:name="android.permission.INTERNET"/>

2. Check for Internet Availibility and the State as Active or Inactive.

        public class InternetDemo extends Activity
        {
            @Override
            protected void onCreate(Bundle savedInstanceState) {
                super.onCreate(savedInstanceState);
                setContentView(R.layout.activity_main);

                checkInternetAvailibility();
            }

            public void checkInternetAvailibility()
            {
                if(isInternetAvailable())
                {
                    new IsInternetActive().execute();
                }
                else {
                    Toast.makeText(getApplicationContext(), "Internet Not Connected", Toast.LENGTH_LONG).show();
                }
            }

            public boolean isInternetAvailable() {
                try {
                    ConnectivityManager connectivityManager
                            = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
                    NetworkInfo activeNetworkInfo = connectivityManager.getActiveNetworkInfo();
                    return activeNetworkInfo != null && activeNetworkInfo.isConnected();
                } catch (Exception e) {

                    Log.e("isInternetAvailable:",e.toString());
                    return false;
                }
            }

            class IsInternetActive extends AsyncTask<Void, Void, String>
            {
                InputStream is = null;
                String json = "Fail";

                @Override
                protected String doInBackground(Void... params) {
                    try {
                        URL strUrl = new URL("http://icons.iconarchive.com/icons/designbolts/handstitch-social/24/Android-icon.png");
                        //Here I have taken one android small icon from server, you can put your own icon on server and access your URL, otherwise icon may removed from another server.

                        URLConnection connection = strUrl.openConnection();
                        connection.setDoOutput(true);
                        is =  connection.getInputStream();
                        json = "Success";

                    } catch (Exception e) {
                        e.printStackTrace();
                        json = "Fail";
                    }
                    return json;

                }

                @Override
                protected void onPostExecute(String result) {
                    if (result != null)
                    {
                       if(result.equals("Fail"))
                       {
                           Toast.makeText(getApplicationContext(), "Internet Not Active", Toast.LENGTH_LONG).show();
                       }
                       else
                       {
                           Toast.makeText(getApplicationContext(), "Internet Active " + result, Toast.LENGTH_LONG).show();
                       }
                    }
                    else
                    {
                        Toast.makeText(getApplicationContext(), "Internet Not Active", Toast.LENGTH_LONG).show();
                    }
                }

                @Override
                protected void onPreExecute() {
                    Toast.makeText(getBaseContext(),"Validating Internet",Toast.LENGTH_LONG).show();
                    super.onPreExecute();
                }
            }
        }

How can I check internet connection in Android Q?

Use this code snippet.

     @IntRange(from = 0, to = 3)
public static int getConnectionType(Context context) {
    int result = 0; // Returns connection type. 0: none; 1: mobile data; 2: wifi
    ConnectivityManager cm = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
        if (cm != null) {
            NetworkCapabilities capabilities = cm.getNetworkCapabilities(cm.getActiveNetwork());
            if (capabilities != null) {
                if (capabilities.hasTransport(NetworkCapabilities.TRANSPORT_WIFI)) {
                    result = 2;
                } else if (capabilities.hasTransport(NetworkCapabilities.TRANSPORT_CELLULAR)) {
                    result = 1;
                } else if (capabilities.hasTransport(NetworkCapabilities.TRANSPORT_VPN)) {
                    result = 3;
                }
            }
        }
    } else {
        if (cm != null) {
            NetworkInfo activeNetwork = cm.getActiveNetworkInfo();
            if (activeNetwork != null) {
                // connected to the internet
                if (activeNetwork.getType() == ConnectivityManager.TYPE_WIFI) {
                    result = 2;
                } else if (activeNetwork.getType() == ConnectivityManager.TYPE_MOBILE) {
                    result = 1;
                } else if (activeNetwork.getType() == ConnectivityManager.TYPE_VPN) {
                    result = 3;
                }
            }
        }
    }
    return result;
}

Detect whether there is an Internet connection available on Android

The getActiveNetworkInfo() method of ConnectivityManager returns a NetworkInfo instance representing the first connected network interface it can find or null if none of the interfaces are connected. Checking if this method returns null should be enough to tell if an internet connection is available or not.

private boolean isNetworkAvailable() {
    ConnectivityManager connectivityManager 
          = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
    NetworkInfo activeNetworkInfo = connectivityManager != null ? connectivityManager.getActiveNetworkInfo() : null;
    return activeNetworkInfo != null && activeNetworkInfo.isConnected();
}

You will also need:

<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />

in your android manifest.

Edit:

Note that having an active network interface doesn't guarantee that a particular networked service is available. Network issues, server downtime, low signal, captive portals, content filters and the like can all prevent your app from reaching a server. For instance you can't tell for sure if your app can reach Twitter until you receive a valid response from the Twitter service.

Check internet connectivity android in kotlin

Call the AsyncTask this way, it should work. You don't need to change anything in your InternetCheck AsyncTask. Basically you need to pass in an object that implements the Consumer interface that's defined in the InternetCheck class.

InternetCheck(object : InternetCheck.Consumer {
    override fun accept(internet: Boolean?) {
        Log.d("test", "asdasdas")
    }
})

How to check internet access on Android? InetAddress never times out

Network connection / Internet access

• isConnectedOrConnecting() (used in most answers) checks for any network connection
• To know whether any of those networks have internet access, use one of the following

A) Ping a Server (easy)

// ICMP 
public boolean isOnline() {
    Runtime runtime = Runtime.getRuntime();
    try {
        Process ipProcess = runtime.exec("/system/bin/ping -c 1 8.8.8.8");
        int     exitValue = ipProcess.waitFor();
        return (exitValue == 0);
    }
    catch (IOException e)          { e.printStackTrace(); }
    catch (InterruptedException e) { e.printStackTrace(); }

    return false;
}

+ could run on main thread

- does not work on some old devices (Galays S3, etc.), it blocks a while if no internet is available.

B) Connect to a Socket on the Internet (advanced)

// TCP/HTTP/DNS (depending on the port, 53=DNS, 80=HTTP, etc.)
public boolean isOnline() {
    try {
        int timeoutMs = 1500;
        Socket sock = new Socket();
        SocketAddress sockaddr = new InetSocketAddress("8.8.8.8", 53);

        sock.connect(sockaddr, timeoutMs);
        sock.close();

        return true;
    } catch (IOException e) { return false; }
}

+ very fast (either way), works on all devices, very reliable

- can't run on the UI thread

This works very reliably, on every device, and is very fast. It needs to run in a separate task though (e.g. ScheduledExecutorService or AsyncTask).

Possible Questions

• Is it really fast enough?

  Yes, very fast ;-)

• Is there no reliable way to check internet, other than testing something on the internet?

  Not as far as I know, but let me know, and I will edit my answer.

• What if the DNS is down?

  Google DNS (e.g. 8.8.8.8) is the largest public DNS in the world. As of 2018 it handled over a trillion queries a day [1]. Let 's just say, your app would probably not be the talk of the day.

• Which permissions are required?

  <uses-permission android:name="android.permission.INTERNET" />
  

  Just internet access - surprise ^^ (Btw have you ever thought about, how some of the methods suggested here could even have a remote glue about internet access, without this permission?)

 

Extra: One-shot RxJava/RxAndroid Example (Kotlin)

fun hasInternetConnection(): Single<Boolean> {
  return Single.fromCallable {
    try {
      // Connect to Google DNS to check for connection
      val timeoutMs = 1500
      val socket = Socket()
      val socketAddress = InetSocketAddress("8.8.8.8", 53)
    
      socket.connect(socketAddress, timeoutMs)
      socket.close()
  
      true
    } catch (e: IOException) {
      false
    }
  }
  .subscribeOn(Schedulers.io())
  .observeOn(AndroidSchedulers.mainThread())
}

///////////////////////////////////////////////////////////////////////////////////
// Usage

    hasInternetConnection().subscribe { hasInternet -> /* do something */}

Extra: One-shot RxJava/RxAndroid Example (Java)

public static Single<Boolean> hasInternetConnection() {
    return Single.fromCallable(() -> {
        try {
            // Connect to Google DNS to check for connection
            int timeoutMs = 1500;
            Socket socket = new Socket();
            InetSocketAddress socketAddress = new InetSocketAddress("8.8.8.8", 53);

            socket.connect(socketAddress, timeoutMs);
            socket.close();

            return true;
        } catch (IOException e) {
            return false;
        }
    }).subscribeOn(Schedulers.io()).observeOn(AndroidSchedulers.mainThread());
}

///////////////////////////////////////////////////////////////////////////////////
// Usage

    hasInternetConnection().subscribe((hasInternet) -> {
        if(hasInternet) {

        }else {

        }
    });

Extra: One-shot AsyncTask Example

Caution: This shows another example of how to do the request. However, since AsyncTask is deprecated, it should be replaced by your App's thread scheduling, Kotlin Coroutines, Rx, ...

class InternetCheck extends AsyncTask<Void,Void,Boolean> {

    private Consumer mConsumer;
    public  interface Consumer { void accept(Boolean internet); }

    public  InternetCheck(Consumer consumer) { mConsumer = consumer; execute(); }

    @Override protected Boolean doInBackground(Void... voids) { try {
        Socket sock = new Socket();
        sock.connect(new InetSocketAddress("8.8.8.8", 53), 1500);
        sock.close();
        return true;
    } catch (IOException e) { return false; } }

    @Override protected void onPostExecute(Boolean internet) { mConsumer.accept(internet); }
}

///////////////////////////////////////////////////////////////////////////////////
// Usage

    new InternetCheck(internet -> { /* do something with boolean response */ });

How to check Internet access at realtime?

Here's something I cooked earlier; maybe it will help:

    public class NetworkStateMonitor extends BroadcastReceiver {
        Context mContext;
        boolean mIsUp;

        public interface Listener {
            void onNetworkStateChange(boolean up);
        }

        public NetworkStateMonitor(Context context) {
            mContext = context;
            //mListener = (Listener)context;
            IntentFilter intentFilter = new IntentFilter(ConnectivityManager.CONNECTIVITY_ACTION);
            context.registerReceiver(this, intentFilter);
            mIsUp = isUp();
        }

        /**
        * call this when finished with it, and no later than onStop(): callback will crash if app has been destroyed
        */
        public void unregister() {  
            mContext.unregisterReceiver(this);
        }

        /*
        * can be called at any time
        */
        public boolean isUp() {
            ConnectivityManager connectivityManager = (ConnectivityManager) mContext.getSystemService(Context.CONNECTIVITY_SERVICE);
            NetworkInfo activeNetworkInfo = connectivityManager.getActiveNetworkInfo();
            return activeNetworkInfo!=null && activeNetworkInfo.isConnectedOrConnecting();
        }

        /**
        * registerReceiver callback, passed to mListener
        */
        @Override public void onReceive(Context context, Intent intent) {       
            boolean upNow = isUp();
            if (upNow == mIsUp) return;     // no change
            mIsUp = upNow;
            ((Listener)mContext).onNetworkStateChange(mIsUp);
        }
    }

---

Related Topics