Element: blur event - Web APIs 编辑

The blur event fires when an element has lost focus. The main difference between this event and focusout is that focusout bubbles while blur does not.

The opposite of blur is focus.

Examples

Simple example

HTML

<form id="form">
  <input type="text" placeholder="text input">
  <input type="password" placeholder="password">
</form>

JavaScript

const password = document.querySelector('input[type="password"]');

password.addEventListener('focus', (event) => {
  event.target.style.background = 'pink';
});

password.addEventListener('blur', (event) => {
  event.target.style.background = '';
});

Result

Event delegation

There are two ways of implementing event delegation for this event: by using the focusout event, or by setting the useCapture parameter of addEventListener() to true.

HTML

<form id="form">
  <input type="text" placeholder="text input">
  <input type="password" placeholder="password">
</form>

JavaScript

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

form.addEventListener('focus', (event) => {
  event.target.style.background = 'pink';
}, true);

form.addEventListener('blur', (event) => {
  event.target.style.background = '';
}, true);

Result

Specifications

Browser compatibility

BCD tables only load in the browser

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.

See also

• Related events: focus, focusin, focusout
• This event on Window targets: blur event