/Web APIs

XMLHttpRequest: timeout event

The timeout event is fired when progression is terminated due to preset time expiring.


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


addEventListener("timeout", (event) => {});

ontimeout = (event) => {};

Event type

Event properties

In addition to the properties listed below, properties from the parent interface, Event, are available.

lengthComputable Read only

A boolean flag indicating if the total work to be done, and the amount of work already done, by the underlying process is calculable. In other words, it tells if the progress is measurable or not.

loaded Read only

A 64-bit unsigned integer value indicating the amount of work already performed by the underlying process. The ratio of work done can be calculated by dividing total by the value of this property. When downloading a resource using HTTP, this only counts the body of the HTTP message, and doesn't include headers and other overhead.

total Read only

A 64-bit unsigned integer representing the total amount of work that the underlying process is in the progress of performing. When downloading a resource using HTTP, this is the Content-Length (the size of the body of the message), and doesn't include the headers and other overhead.



const client = new XMLHttpRequest();
client.open("GET", "http://www.example.org/example.txt");
client.ontimeout = () => {


You could also set up the event handler using the addEventListener() method:


client.addEventListener("timeout", () => {


Browser compatibility

Desktop Mobile
Chrome Edge Firefox Internet Explorer Opera Safari WebView Android Chrome Android Firefox for Android Opera Android Safari on IOS Samsung Internet
timeout_event 29 12 12 8 16 7 4.4 29 14 16 7 1.0

See also

© 2005–2023 MDN contributors.
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.