Window: online event

The online event of the Window interface is fired when the browser has gained access to the network and the value of Navigator.onLine switches to true.

Note: This event shouldn't be used to determine the availability of a particular website. Network problems or firewalls might still prevent the website from being reached.


Use the event name in methods like addEventListener(), or set an event handler property.

addEventListener("online", (event) => {});
ononline = (event) => {};

Event type

A generic Event.

Event handler aliases

In addition to the Window interface, the event handler property ononline is also available on the following targets:


// addEventListener version
window.addEventListener("online", (event) => {
  console.log("You are now connected to the network.");

// ononline version
window.ononline = (event) => {
  console.log("You are now connected to the network.");


HTML Standard
# event-online
HTML Standard
# handler-window-ononline

Browser compatibility

BCD tables only load in the browser

See also