#Lan no internet access update
#Lan no internet access software
#Lan no internet access Offline

IE 8 will support the property.Д«ut of course that doesn't help with other browsers or operating systems.

#Lan no internet access update

I initially intended to post this as an update to Grant Wagner's answer, but it seemed too much of an edit, especially considering that the 2014 update was already not from him. To check that, you will still need to use one of the solutions described in the other answers. It does not mean that you have Internet access for example. If it is true however (or you get an online event), it only means the system is connected to some network, at best.

#Lan no internet access Offline

This means that if is false (or you get an offline event), you are guaranteed to have no Internet connection. Until Firefox 41, all other conditions return a true value since Firefox 41, on OS X and Windows, the value will follow the actual network connectivity. In Firefox and Internet Explorer, switching the browser to offline mode sends a false value.

#Lan no internet access software

You could be getting false positives, such as in cases where the computer is running a virtualization software that has virtual ethernet adapters that are always 'connected.' Therefore, if you really want to determine the online status of the browser, you should develop additional means for checking. So while you can assume that the browser is offline when it returns a false value, you cannot assume that a true value necessarily means that the browser can access the internet. In Chrome and Safari, if the browser is not able to connect to a local area network (LAN) or a router, it is offline all other conditions return true. Note however this quote from Mozilla Documentation:

Try setting your system or browser in offline/online mode and check the log or the property for the value changes.

Window.addEventListener('offline', () => console.log('Became offline')) Дocument.getElementById('statusCheck').addEventListener('click', () => console.log(' is ' + )) Click to check the property Window.addEventListener('online', () => console.log('Became online')) You'll have to weight these options out for your specific app.Д¬onsole.log('Initially ' + ( ? 'on' : 'off') + 'line') So again, determining the state of the internet connection as a whole may be more trouble than it's worth. Embedding an image may not really tell us anything, because we need a useful response from the communication mechanism in order to draw a good conclusion about what's going on. Other cross-domain techniques could be tried, for example, embedding an iframe in your page which points to, and then polling the iframe for success/failure (examine the contents, etc). This is a catch-22 because if the internet connection is actually the problem, we won't be able to get to the server, and if the connection problem is only on our own domain, we won't be able to tell the difference. One option is to set up a server-side proxy, wherein we actually ping google (or whatever site), and return the results of the ping to the app. First, we'd have the same cross-domain issues that are typically encountered in making Ajax communications. Sidenote: Sending a Ping could be achieved in the same way that you would make any kind of two-way ajax request, but sending a ping to google, in this case, would pose some challenges. Trying to send a ping to google would be a good way to confirm that the internet connection itself is down, so if that information is useful to you, then it might be worth the trouble. Sidenote: You could check a reliable site like google for connectivity, but this may not be entirely useful as just trying to make your own request, because while Google may be available, your own application may not be, and you're still going to have to handle your own connection problem. allowing them to eventually fix the connection problem if there is one, and to continue using your app with a fair amount of forgiveness. So your best bet may be to just fail gracefully, preserve the data, and alert the user. wireless connections may come and go, etc. Sidenote: To put the entire application in an 'offline' state may lead to a lot of error-prone work of handling state. If it doesn't go through, alert the user to check the connection, and fail gracefully. The standard approach is to retry the request a few times.

You can determine that the connection is lost by making failed XHR requests.