Check internet connection (iOS 10)

Question

For iOS 9 I was using Reachability public class to check wether the device is connected to the internet or not. I converted my Swift 2 code to Swift 3, and the Reachability doesn't work anymore. Can someone tell me how to check the internet connection on iOS 10? Thanks! Here's the code snippet:

open class Reachability {
    class func isConnectedToNetwork() -> Bool {
        var zeroAddress = sockaddr_in()
        zeroAddress.sin_len = UInt8(MemoryLayout.size(ofValue: zeroAddress))
        zeroAddress.sin_family = sa_family_t(AF_INET)
        let defaultRouteReachability = withUnsafePointer(to: &zeroAddress) {
            SCNetworkReachabilityCreateWithAddress(nil, UnsafePointer($0))
        }
        var flags = SCNetworkReachabilityFlags()
        if !SCNetworkReachabilityGetFlags(defaultRouteReachability!, &flags) {
            return false
        }
        let isReachable = (flags.rawValue & UInt32(kSCNetworkFlagsReachable)) != 0
        let needsConnection = (flags.rawValue & UInt32(kSCNetworkFlagsConnectionRequired)) != 0
        return (isReachable && !needsConnection)
    }
}

see http://stackoverflow.com/questions/39046377/swift-3-unsafepointer0-no-longer-compile-in-xcode-8-beta-6 — MartinMcB, Sep 18 '16 at 15:18
Please note that http://stackoverflow.com/questions/25623272/how-to-use-scnetworkreachability-in-swift/25623647#25623647 has been updated for Swift 3. — Martin R, Sep 18 '16 at 15:20
I think this will help you with your Q: http://stackoverflow.com/a/39783037/4301118 — sharon, Oct 18 '16 at 06:51
See alamofire answer - https://stackoverflow.com/a/46562290/7576100 — Jack, Oct 04 '17 at 11:04

score 112 · Accepted Answer · edited Jun 21 '17 at 02:12

112

import Foundation
import SystemConfiguration

func isInternetAvailable() -> Bool
    {
        var zeroAddress = sockaddr_in()
        zeroAddress.sin_len = UInt8(MemoryLayout.size(ofValue: zeroAddress))
        zeroAddress.sin_family = sa_family_t(AF_INET)

        let defaultRouteReachability = withUnsafePointer(to: &zeroAddress) {
            $0.withMemoryRebound(to: sockaddr.self, capacity: 1) {zeroSockAddress in
                SCNetworkReachabilityCreateWithAddress(nil, zeroSockAddress)
            }
        }

        var flags = SCNetworkReachabilityFlags()
        if !SCNetworkReachabilityGetFlags(defaultRouteReachability!, &flags) {
            return false
        }
        let isReachable = flags.contains(.reachable)
        let needsConnection = flags.contains(.connectionRequired)
        return (isReachable && !needsConnection)
    }

This works in iOS 10

edited Jun 21 '17 at 02:12

Alexander Vasenin

11,437
4
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70

answered Oct 20 '16 at 08:09

Adnan T.

1,166
1
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8

2

this answer is good but not enough. if you will use this function, you must import SystemConfiguration – Phd. Burak Öztürk Jan 07 '17 at 21:45
7

If you are connected to a wi-fi but not able to connect to the internet (open a google page) still it returns true for reachable. It's wrong. – Arildo Junior Feb 02 '17 at 18:56
4

This returns "true" when connected to the WiFi without the Internet, which is a problem for my case. – Pavle Mijatovic Mar 10 '17 at 09:14
1

@PavleMijatovic so what is the solution to this problem ( returns "true" when connected to the WiFi without the Internet)? If you found out, please let me know as well. – Tejas Jun 27 '17 at 10:48
@Tejas, here is how I implemented inside my code, I just pinged a site if I am on WiFi. You have down below my implementation. – Pavle Mijatovic Jul 26 '17 at 10:03
@PavleMijatovic : Ok, Thank You! :) – Tejas Jul 26 '17 at 10:14
But Apple says that Reachability API MUST only be used for diagnostic purposes. Proactive network check using Reachability is ill advised. Instead Apple wants you to handle it through exception Handling mechanism. – Anjan Biswas Nov 06 '17 at 01:13

Jad · Answer 2 · 2017-01-12T15:23:30.520

63

SWIFT 3.0: Here's very simple way to do it:

import SystemConfiguration


protocol Utilities {
}

extension NSObject:Utilities{


    enum ReachabilityStatus {
        case notReachable
        case reachableViaWWAN
        case reachableViaWiFi
    }

    var currentReachabilityStatus: ReachabilityStatus {

        var zeroAddress = sockaddr_in()
        zeroAddress.sin_len = UInt8(MemoryLayout<sockaddr_in>.size)
        zeroAddress.sin_family = sa_family_t(AF_INET)

        guard let defaultRouteReachability = withUnsafePointer(to: &zeroAddress, {
            $0.withMemoryRebound(to: sockaddr.self, capacity: 1) {
                SCNetworkReachabilityCreateWithAddress(nil, $0)
            }
        }) else {
            return .notReachable
        }

        var flags: SCNetworkReachabilityFlags = []
        if !SCNetworkReachabilityGetFlags(defaultRouteReachability, &flags) {
            return .notReachable
        }

        if flags.contains(.reachable) == false {
            // The target host is not reachable.
            return .notReachable
        }
        else if flags.contains(.isWWAN) == true {
            // WWAN connections are OK if the calling application is using the CFNetwork APIs.
            return .reachableViaWWAN
        }
        else if flags.contains(.connectionRequired) == false {
            // If the target host is reachable and no connection is required then we'll assume that you're on Wi-Fi...
            return .reachableViaWiFi
        }
        else if (flags.contains(.connectionOnDemand) == true || flags.contains(.connectionOnTraffic) == true) && flags.contains(.interventionRequired) == false {
            // The connection is on-demand (or on-traffic) if the calling application is using the CFSocketStream or higher APIs and no [user] intervention is needed
            return .reachableViaWiFi
        } 
        else {
            return .notReachable
        }
    }

}

and then simply you can use it anywhere in your project for example:

  func viewDidLoad(){
      print(currentReachabilityStatus != .notReachable) //true connected
    }

edited Jan 12 '17 at 15:23

answered Nov 13 '16 at 12:49

Jad

2,139
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Thanks this helped me in swift3. – Uma Madhavi Dec 06 '16 at 05:05
3

This one is the best solution. Very Swifty too. – Kegham K. Dec 14 '16 at 00:16
3

If you are connected to a wi-fi but not able to connect to the internet (open a google page) still it returns true for reachable. It's wrong. – Arildo Junior Feb 02 '17 at 18:58
Great solution! Thanks. – richc Mar 03 '17 at 18:17
1

I wish I could give this more than one upvote! Should be the accepted solution. – Scooter Mar 14 '17 at 16:37
I don't normally comment on here, but this solution blew me out of the water! Absolutely perfect! – Frank Minyon Mar 16 '17 at 15:33
can we also check for mobile cellular data?? So, that user can choose to use WiFi or, cellular data within the app. – Aashish Apr 13 '17 at 05:36
This returns "true" when connected to the WiFi without the Internet, which is a problem for my case. – Codetard Sep 11 '17 at 13:22
This code fails to work when wifi is connected but internet is not available – Tina Sep 22 '17 at 10:57
How can I add a functionality for callback when the reachability status changes? – Nikhil Manapure Oct 05 '17 at 12:34
Type 'SCNNetworkReachabilityFlags' has no member 'isWWAN'. Red error. Could someone help me out? Seems to be updated in Swift 4.0?! – j3141592653589793238 Oct 30 '17 at 11:12

Patel Jigar · Answer 3 · 2017-05-31T12:13:11.580

11

Try this, it works for me first import the SystemConfiguration to your class.

import SystemConfiguration

And now implement bellow function.

func isConnectedToNetwork() -> Bool {

    var zeroAddress = sockaddr_in(sin_len: 0, sin_family: 0, sin_port: 0, sin_addr: in_addr(s_addr: 0), sin_zero: (0, 0, 0, 0, 0, 0, 0, 0))
    zeroAddress.sin_len = UInt8(MemoryLayout.size(ofValue: zeroAddress))
    zeroAddress.sin_family = sa_family_t(AF_INET)
    let defaultRouteReachability = withUnsafePointer(to: &zeroAddress) {
        $0.withMemoryRebound(to: sockaddr.self, capacity: 1) {zeroSockAddress in
            SCNetworkReachabilityCreateWithAddress(nil, zeroSockAddress)
        }
    }

    var flags = SCNetworkReachabilityFlags()
    if !SCNetworkReachabilityGetFlags(defaultRouteReachability!, &flags) {
        return false
    }
    let isReachable = (flags.rawValue & UInt32(kSCNetworkFlagsReachable)) != 0
    let needsConnection = (flags.rawValue & UInt32(kSCNetworkFlagsConnectionRequired)) != 0

    return (isReachable && !needsConnection)

}

edited May 31 '17 at 12:13

answered Nov 08 '16 at 05:24

Patel Jigar

2,141
1
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It appears there is a flaw in this code. Checking for flags with == doesn't work properly. – ryantxr Dec 27 '16 at 15:34
dear @ryantxr this code works properly for me, i hope u are using swift 3.0, and if you find the better solution for this, then you can put it here, please dont downmark the answer – Patel Jigar Dec 28 '16 at 05:10
1

You can fix it with `flags.contains(.reachable)` and `flags.contains(.connectionRequired)`. Yes I am using Swift 3. – ryantxr Dec 29 '16 at 01:24
3

If you are connected to a wi-fi but not able to connect to the internet (open a google page) still it returns true for reachable. It's wrong. – Arildo Junior Feb 02 '17 at 18:54
This code is giving me a problem. Its works properly for WiFi but if I connect using cellular data and check, it says no internet even though the internet is available. – miOS May 03 '17 at 06:55
@ArildoJunior Make a response data check. Like if the response data is nil, then you're offline. – Codetard Sep 14 '17 at 12:23

Krutagn Patel · Answer 4 · 2017-03-30T05:42:21.603

step 1 : create a swift file in your project. i created "ConnectionCheck.swift"

step 2 : add this code in your "ConnectionCheck.swift" file and "import SystemConfiguration" file to your "ConnectionCheck.swift" and "ViewController.swift"

import Foundation
import SystemConfiguration
public class ConnectionCheck {

class func isConnectedToNetwork() -> Bool {

    var zeroAddress = sockaddr_in()
    zeroAddress.sin_len = UInt8(MemoryLayout<sockaddr_in>.size)
    zeroAddress.sin_family = sa_family_t(AF_INET)

    guard let defaultRouteReachability = withUnsafePointer(to: &zeroAddress, {
        $0.withMemoryRebound(to: sockaddr.self, capacity: 1) {
            SCNetworkReachabilityCreateWithAddress(nil, $0)
        }
    }) else {
        return false
    }

    var flags: SCNetworkReachabilityFlags = []
    if !SCNetworkReachabilityGetFlags(defaultRouteReachability, &flags) {
        return false
    }

    let isReachable = flags.contains(.reachable)
    let needsConnection = flags.contains(.connectionRequired)

    return (isReachable && !needsConnection)
}

}

step 3 : Now in "ViewController.swift" use this code to check Network Reachability

if ConnectionCheck.isConnectedToNetwork() {
        print("Connected")
    }
    else{
        print("disConnected")
    }

If I submit my app to apple, do I need to change any code in order to pass apple verification？ — Eric Chong, Aug 08 '17 at 01:22
@LOLXDXPLOL yes, we can see... But SO work with multiple answer so others can see different version and maybe, just maybe, a better solution shows up... I'm trying to remain polite. — Byron Coetsee, Oct 20 '17 at 11:57
@ByronCoetsee sorry, I didn’t want to sound impolite, I just didn’t think of it that way. Thanks! — LOLXDXPLOL, Oct 20 '17 at 12:01

Junaid Ali · Answer 5 · 2017-10-16T17:31:58.197

This code would be helpful for you. it worked for me in Swift 4 and Xcode 9

Go to https://github.com/ashleymills/Reachability.swift/tree/master/Reachability and copy Reachability.swift file to your project

Vasil Nunev clearly explain this Reachability https://www.youtube.com/watch?v=wDZmz9IsB-8

class ViewController: UIViewController {

   let reachability = Reachability();
    override func viewDidLoad() {
        super.viewDidLoad()

        reachability?.whenReachable = { _ in

            DispatchQueue.main.async {
                self.view.backgroundColor = UIColor.green
            }
        }

        reachability?.whenUnreachable = { _ in
            DispatchQueue.main.async {
                self.view.backgroundColor = UIColor.red
            }
        }
        NotificationCenter.default.addObserver(self, selector: #selector(internetChanged), name: Notification.Name.reachabilityChanged , object: reachability)
        do{

            try reachability?.startNotifier()
        }catch{
            print("Could not start notifier:\(error)")
        }

    }

    @objc func internetChanged(note:Notification)  {
        let reachability  = note.object as! Reachability

        if reachability.connection != .none {

            if reachability.connection == .wifi{
                DispatchQueue.main.async {
                    self.view.backgroundColor = #colorLiteral(red: 0.3411764801, green: 0.6235294342, blue: 0.1686274558, alpha: 1)
                }
            }else if reachability.connection == .cellular{
                DispatchQueue.main.async {
                    self.view.backgroundColor = #colorLiteral(red: 0.3647058904, green: 0.06666667014, blue: 0.9686274529, alpha: 1)
                }
            }
        }else{
            DispatchQueue.main.async {
                self.view.backgroundColor = #colorLiteral(red: 0.7450980544, green: 0.1568627506, blue: 0.07450980693, alpha: 1)
            }
        }
    }
}

Does this method work for cellular data as well as wifi? And does it distinguish between simply being connected to wifi and being connect to wifi *with* internet connection? — Runeaway3, Nov 01 '17 at 01:53
This code is not working for me. I dont know what am I doing wrong. It return true and then false when you get in network. — iOS_Developer, Nov 02 '17 at 16:07

score 3 · Answer 6 · answered Jul 26 '17 at 10:07

Here is Swift 3 solution via callback function, isConnectedToNetwork() is taken from the solution by Yasin Ugurlu from above.

class func isInternetAvailable(webSiteToPing: String?, completionHandler: @escaping (Bool) -> Void) {

    // 1. Check the WiFi Connection
    guard isConnectedToNetwork() else {
      completionHandler(false)
      return
    }

    // 2. Check the Internet Connection
    var webAddress = "https://www.google.com" // Default Web Site
    if let _ = webSiteToPing {
      webAddress = webSiteToPing!
    }

    guard let url = URL(string: webAddress) else {
      completionHandler(false)
      print("could not create url from: \(webAddress)")
      return
    }

    let urlRequest = URLRequest(url: url)
    let session = URLSession.shared
    let task = session.dataTask(with: urlRequest, completionHandler: { (data, response, error) in
      if error != nil || response == nil {
        completionHandler(false)
      } else {
        completionHandler(true)
      }
    })

    task.resume()
  }

your answer looks good and your comment above about the accepted answer connecting to wifi but no internet is correct. How do you call your function and use it inside a view controller? Please show an example — Lance Samaria, Feb 23 '18 at 06:08

FRIDDAY · Answer 7 · 2018-10-14T14:46:59.347

Swift 4 / Xcode 10:

I would combine two functions ( with a bit changes) are taken from the solutions by @Pavle Mijatovic and @Krutagn Patel (with thanks) to answer @Lance Samaria question. :)

I almost checked all the possibilities. (the code can be enhanced, but it works fine)

have a class as below:

import Foundation
import SystemConfiguration

public class ConnectionCheck {

    class func isConnectedToNetwork() -> Bool {

        var zeroAddress = sockaddr_in()
        zeroAddress.sin_len = UInt8(MemoryLayout<sockaddr_in>.size)
        zeroAddress.sin_family = sa_family_t(AF_INET)

        guard let defaultRouteReachability = withUnsafePointer(to: &zeroAddress, {
            $0.withMemoryRebound(to: sockaddr.self, capacity: 1) {
                SCNetworkReachabilityCreateWithAddress(nil, $0)
            }
        }) else {
            return false
        }

        var flags: SCNetworkReachabilityFlags = []
        if !SCNetworkReachabilityGetFlags(defaultRouteReachability, &flags) {
            return false
        }

        let isReachable = flags.contains(.reachable)
        let needsConnection = flags.contains(.connectionRequired)

        return (isReachable && !needsConnection)
    }


    class func isInternetAvailable(webSiteToPing: String?, completionHandler: @escaping (_ b: Bool) -> Void) {

        // 1. Check the WiFi Connection
        guard isConnectedToNetwork() else {
            completionHandler(false)
            return
        }

        // 2. Check the Internet Connection
        var webAddress = "https://www.google.com" // Default Web Site
        if let _ = webSiteToPing {
            webAddress = webSiteToPing!
        }

        guard let url = URL(string: webAddress) else {
            completionHandler(false)
            print("could not create url from: \(webAddress)")
            return
        }

        let urlRequest = URLRequest(url: url)
        let session = URLSession.shared
        let task = session.dataTask(with: urlRequest, completionHandler: { (data, response, error) in
            if error != nil || response == nil {
                completionHandler(false)
            } else {
                completionHandler(true)
            }
        })

        task.resume()
    }
}

use the below code where you need to check the Internet connection: for example, in appDelegate -> applicationDidBecomeActive function.

explanation: whenever completionHandler function (above) is called, the result (true or false) is passed to the below code as b. so if b is true you have the Internet connection.

let web : String? = "https://www.google.com"
ConnectionCheck.isInternetAvailable(webSiteToPing: web) { (b)  in
 print(b)
if b {
print("connected") // or do something here
    } else {
print("disconnected") // or do something here
}
}

score 0 · Answer 8 · answered Mar 17 '17 at 13:04

You can use in swift 3

import SystemConfiguration

class Connection {

    class func isConnectedToNetwork() -> Bool {

        var zeroAddress = sockaddr_in(sin_len: 0, sin_family: 0, sin_port: 0, sin_addr: in_addr(s_addr: 0), sin_zero: (0, 0, 0, 0, 0, 0, 0, 0))
        zeroAddress.sin_len = UInt8(sizeofValue(zeroAddress))
        zeroAddress.sin_family = sa_family_t(AF_INET)

        let defaultRouteReachability = withUnsafePointer(&zeroAddress) {
            SCNetworkReachabilityCreateWithAddress(kCFAllocatorDefault, UnsafePointer($0))
        }

        var flags: SCNetworkReachabilityFlags = SCNetworkReachabilityFlags(rawValue: 0)
        if SCNetworkReachabilityGetFlags(defaultRouteReachability!, &flags) == false {
            return false
        }

        let isReachable = (flags.rawValue & UInt32(kSCNetworkFlagsReachable)) != 0
        let needsConnection = (flags.rawValue & UInt32(kSCNetworkFlagsConnectionRequired)) != 0

        return isReachable && !needsConnection

    }
}

score 0 · Answer 9 · answered Aug 01 '18 at 07:33

1) Create a new Swift file within your project, name it “Reachability.swift”.

2) Cut & paste the following code into it to create your class.

import Foundation
import SystemConfiguration

public class Reachability {

class func isConnectedToNetwork() -> Bool {

    var zeroAddress = sockaddr_in(sin_len: 0, sin_family: 0, sin_port: 0, sin_addr: in_addr(s_addr: 0), sin_zero: (0, 0, 0, 0, 0, 0, 0, 0))
    zeroAddress.sin_len = UInt8(sizeofValue(zeroAddress))
    zeroAddress.sin_family = sa_family_t(AF_INET)

    let defaultRouteReachability = withUnsafePointer(&zeroAddress) {
        SCNetworkReachabilityCreateWithAddress(kCFAllocatorDefault, UnsafePointer($0))
    }

    var flags: SCNetworkReachabilityFlags = SCNetworkReachabilityFlags(rawValue: 0)
    if SCNetworkReachabilityGetFlags(defaultRouteReachability!, &flags) == false {
        return false
    }

    let isReachable = flags == .Reachable
    let needsConnection = flags == .ConnectionRequired

    return isReachable && !needsConnection

     }
}

3) You can check internet connection anywhere in your project using this code:

 if Reachability.isConnectedToNetwork() == true {
println("Internet connection OK")
} else {
println("Internet connection FAILED")
}

4)If the user is not connected to the internet, you may want to show them an alert dialog to notify them.

if Reachability.isConnectedToNetwork() == true {
println("Internet connection OK")
} else {
println("Internet connection FAILED")
var alert = UIAlertView(title: "No Internet Connection", message: "Make sure your 
 device is connected to the internet.", delegate: nil, cancelButtonTitle: "OK")
alert.show()
}

itsmcgh · Answer 10 · 2018-10-26T01:37:25.213

Swift 4/Xcode 9+ (make Reachability.swift file):

public class Reachability {

    class func isConnectedToNetwork() -> Bool {

        var zeroAddress = sockaddr_in(sin_len: 0, sin_family: 0, sin_port: 0, sin_addr: in_addr(s_addr: 0), sin_zero: (0, 0, 0, 0, 0, 0, 0, 0))
        zeroAddress.sin_len = UInt8(MemoryLayout.size(ofValue: zeroAddress))
        zeroAddress.sin_family = sa_family_t(AF_INET)

        let defaultRouteReachability = withUnsafePointer(to: &zeroAddress) {
            $0.withMemoryRebound(to: sockaddr.self, capacity: 1) {zeroSockAddress in
                SCNetworkReachabilityCreateWithAddress(nil, zeroSockAddress)
            }
        }

        var flags: SCNetworkReachabilityFlags = SCNetworkReachabilityFlags(rawValue: 0)
        if SCNetworkReachabilityGetFlags(defaultRouteReachability!, &flags) == false {
            return false
        }

        // Working for Cellular and WIFI
        let isReachable = (flags.rawValue & UInt32(kSCNetworkFlagsReachable)) != 0
        let needsConnection = (flags.rawValue & UInt32(kSCNetworkFlagsConnectionRequired)) != 0
        let ret = (isReachable && !needsConnection)

        return ret

    }
}

usage:

if Reachability.isConnectedToNetwork() {
// connected, do something
}

score 0 · Answer 11 · edited Oct 26 '18 at 07:25

Create a Swift file within your project, name it: Reachability.swift". then paste below code in this Reachability.swift file:-

import Foundation

import SystemConfiguration

public class Reachability {

    class func isConnectedToNetwork() -> Bool {

        var zeroAddress = sockaddr_in(sin_len: 0, sin_family: 0, sin_port: 0, sin_addr: in_addr(s_addr: 0), sin_zero: (0, 0, 0, 0, 0, 0, 0, 0))
        zeroAddress.sin_len = UInt8(sizeofValue(zeroAddress))
        zeroAddress.sin_family = sa_family_t(AF_INET)

        let defaultRouteReachability = withUnsafePointer(&zeroAddress) {
            SCNetworkReachabilityCreateWithAddress(kCFAllocatorDefault, UnsafePointer($0))
        }

        var flags: SCNetworkReachabilityFlags = SCNetworkReachabilityFlags(rawValue: 0)
        if SCNetworkReachabilityGetFlags(defaultRouteReachability!, &flags) == false {
            return false
        }

        let isReachable = flags == .Reachable
        let needsConnection = flags == .ConnectionRequired

        return isReachable && !needsConnection

    }
}

Then you can check the internet anywhere in the project using below code

  if Reachability.isConnectedToNetwork() == true {
        println("Internet connection OK")
    } else {
        println("Internet connection FAILED")
    }

score 0 · Answer 12 · answered Nov 27 '18 at 13:40

Another solution for Swift 4.0. Not a big fan o IUO rather use a guard

 func isConnectedToNetwork() -> Bool {
    var zeroAddress = sockaddr_in()
    zeroAddress.sin_len = UInt8(MemoryLayout.size(ofValue: zeroAddress))
    zeroAddress.sin_family = sa_family_t(AF_INET)

    guard let defaultRouteReachability = withUnsafePointer(to: &zeroAddress, {
        $0.withMemoryRebound(to: sockaddr.self, capacity: 1) {
            SCNetworkReachabilityCreateWithAddress(nil, $0)
        }
    }) else {
        return false
    }

    var flags: SCNetworkReachabilityFlags = SCNetworkReachabilityFlags(rawValue: 0)
    if SCNetworkReachabilityGetFlags(defaultRouteReachability, &flags) == false {
        return false
    }

    let isReachable = flags == .reachable
    let needsConnection = flags == .connectionRequired
    return isReachable && !needsConnection
}

Check internet connection (iOS 10)

12 Answers12

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