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Offline Detection

This lesson is part of How To · All levels

Summary

Offline detection allows pages to notify users when a connection is disconnected. The browser provides navigator.onLine as well as online and offline events that JavaScript can monitor. But this status is only an estimate of the network connection, not a guarantee that the destination server is actually accessible.

Key points

Navigator.onLine is worth true or false to estimate connection status
Online and offline events installed on the window
Display a banner or a status message so that the user knows the condition of the connection
To ensure server access, you still need real request verification

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