What type of offline?

[juanfernandes]

I tested this by disconnection my network connection while on the demo site and it didn't detect I had lost my connection.

So is this script only for mobile devices? Or for when the browser is set to Work Offline ?

[oskarkrawczyk]

Offline, meaning your internet connection is gone or you completely disconnect wifi/ethernet.

I've explained what can be the cause of this lib not working for everyone here: #2 (comment)