Window: blur event

The blur event fires when an element has lost focus.

The opposite of blur is focus.

Bubbles	No
Cancelable	No
Interface	`FocusEvent`
Event handler property	`onblur`
Sync / Async	Sync
Composed	Yes

Examples

Live example

This example changes the appearance of a document when it loses focus. It uses addEventListener() to monitor focus and blur events.

HTML

<p id="log">Click on this document to give it focus.</p>

CSS

.paused {
  background: #ddd;
  color: #555;
}

JavaScript

function pause() {
  document.body.classList.add('paused');
  log.textContent = 'FOCUS LOST!';
}

function play() {
  document.body.classList.remove('paused');
  log.textContent = 'This document has focus. Click outside the document to lose focus.';
}

const log = document.getElementById('log');

window.addEventListener('blur', pause);
window.addEventListener('focus', play);

Result

Specifications

Specification
UI Events # event-type-blur

The value of Document.activeElement varies across browsers while this event is being handled (bug 452307): IE10 sets it to the element that the focus will move to, while Firefox and Chrome often set it to the body of the document.