Firefox Tomorrow

web api event

Window: focus event

View on MDN ↗

The focus event fires when an element has received focus.

The opposite of focus is blur.

This event is not cancelable and does not bubble.

Syntax

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

addEventListener("focus", (event) => { })

onfocus = (event) => { }

Event type

A FocusEvent. Inherits from UIEvent and Event.

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: #dddddd;
  color: #555555;
}

JavaScript

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

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.";
}

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

Result

Interactive exampleOpen the canonical MDN source to run this embedded demo.

Specifications

SpecificationsStandards references are available on the canonical MDN page.

Browser compatibility

Browser compatibilityCompatibility data is available on the canonical MDN page.

See also

  • Related event: blur
  • This event on Element targets: focus event