Check internet using ConnectivityManager. Supports API 16 and above.

NetworkHelper.kt

import android.net.ConnectivityManager
import android.net.NetworkCapabilities
import android.os.Build

class NetworkHelper(private val connectivityManager: ConnectivityManager) {

    fun isNetworkConnected(): Boolean {
        var result = false
        when {
            Build.VERSION.SDK_INT >= Build.VERSION_CODES.M -> {
                val networkCapabilities = connectivityManager.activeNetwork ?: return false
                val activeNetwork =
                    connectivityManager.getNetworkCapabilities(networkCapabilities) ?: return false
                result = when {
                    activeNetwork.hasTransport(NetworkCapabilities.TRANSPORT_WIFI) -> true
                    activeNetwork.hasTransport(NetworkCapabilities.TRANSPORT_CELLULAR) -> true
                    activeNetwork.hasTransport(NetworkCapabilities.TRANSPORT_ETHERNET) -> true
                    else -> false
                }
            }
            Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP -> {
                connectivityManager.run {
                    connectivityManager.activeNetworkInfo?.run {
                        result = when (type) {
                            ConnectivityManager.TYPE_WIFI -> true
                            ConnectivityManager.TYPE_MOBILE -> true
                            ConnectivityManager.TYPE_ETHERNET -> true
                            else -> false
                        }
                    }
                }
            }
            else -> {
                val networkInfo = connectivityManager.activeNetworkInfo
                result = networkInfo != null && networkInfo.isConnected
            }
        }
        return result
    }
}