Question

This is related to my previous question, but will navigator.onLine work if there is a bad connection? For example, the device is connected to a router, but no pages will load, or anything else that will bring an error that tells the user to check their connection. I know navigator.onLine works when completely disabling a connection, but there just isn’t a way to simulate a bad connection unless you experience a bad connection. If it doesn’t work, are there any tests I could do with javascript to ping a server?

Answer 1

From the documentation:

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. 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 other words, a bad connection will return true.

To answer your second question, yes, you can ping a server with an AJAX call to your server. If it is successful (you get a response back) then you know the browser is online. If it times out, the user could be experiencing a bad connection.