Window: offline event

{{APIRef}} 

The offline event of the {{domxref("Window")}}  interface is fired when the browser has lost access to the network and the value of {{domxref("Navigator.onLine")}}  switches to false.

Syntax

Use the event name in methods like {{domxref("EventTarget.addEventListener", "addEventListener()")}} , or set an event handler property.

addEventListener("offline", (event) => {});
onoffline = (event) => {};

Event type

A generic {{domxref("Event")}} .

Event handler aliases

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

• {{domxref("HTMLBodyElement")}} 
• {{domxref("HTMLFrameSetElement")}} 
• {{domxref("SVGSVGElement")}} 

Examples

// addEventListener version
window.addEventListener("offline", (event) => {
  console.log("The network connection has been lost.");
});

// onoffline version
window.onoffline = (event) => {
  console.log("The network connection has been lost.");
};

Specifications

{{Specifications}} 

Browser compatibility

{{Compat}} 

See also

• online