iPhone active network type (2G, 3G, WiFi)

The SCNetworkReachability interface can help you with that. Basically, you create a so-called reachability reference and then call SCNetworkReachabilityGetFlags on it to get information about the connection.

The returned flags include kSCNetworkReachabilityFlagsIsWWAN, which tells you whether you are connected via WiFi or the cell network. AFAIK it cannot be used to tell the difference between 2G and 3G, though.

See Apple's Reachability sample app for an implementation. In most cases, you should be able to directly use the included Reachability class in your project.

Go to the Apple Developer site, and download a sample project called "Reachability"

It provides an example of what you would like to do.

It is worth noting that I don't believe that you can tell the difference between EDGE(2G) and a 3G connection. It's either WiFi or WWAN.

This is the way to find the network mode(2G,3G,4G or wifi) of your device in swift.

if let reachability = Reachability.forInternetConnection() {

        reachability.startNotifier()

        let status = reachability.currentReachabilityStatus()

        if status == .init(0) {
            // .NotReachable

            print("Not Reachable")

        }
        else if status == .init(1) {
            // .ReachableViaWiFi

            print("Reachable Via WiFi")

        }
        else if status == .init(2) {
            // .ReachableViaWWAN
            let netInfo = CTTelephonyNetworkInfo()

            if let cRAT = netInfo.currentRadioAccessTechnology  {

                switch cRAT {

                case CTRadioAccessTechnologyGPRS,
                     CTRadioAccessTechnologyEdge,
                     CTRadioAccessTechnologyCDMA1x:

                    print("Reachable Via 2G")


                    do{
                        try realm.write {
                            realm.add(ModalDataSaver.singletonClass)
                        }
                    }catch
                    {
                        print("Error in saving data :- \(error.localizedDescription)")
                    }


                case CTRadioAccessTechnologyWCDMA,
                     CTRadioAccessTechnologyHSDPA,
                     CTRadioAccessTechnologyHSUPA,
                     CTRadioAccessTechnologyCDMAEVDORev0,
                     CTRadioAccessTechnologyCDMAEVDORevA,
                     CTRadioAccessTechnologyCDMAEVDORevB,
                     CTRadioAccessTechnologyeHRPD:

                    print("Reachable Via 3G")

                case CTRadioAccessTechnologyLTE:

                    print("Reachable Via 4G")

                default:

                    fatalError("error")

                }
            }
        }
    }