CSS - :hover

The :hover CSS pseudo-class matches when the user designates an element with a pointing device, but does not necessarily activate it. This style may be overridden by any other link-related pseudo-classes, that is :link, :visited, and :active, appearing in subsequent rules. In order to style appropriately links, you need to put the :hover rule after the :link and :visited rules but before the :active one, as defined by the LVHA-order: :link:visited:hover:active.

Examples

Example1

CSS
:link:hover { outline: dotted red; }

.foo:hover { background: gold; }

Dropdown menu

With the :hover pseudo-class you can create complex cascade algorithms. This is a common technique used, for example, in order to create pure-CSS dropdown menus (that is only CSS, without using JavaScript). The essence of this technique is the creation of a rule like the following:

CSS
div.menu-bar ul ul {
  display: none;
}

div.menu-bar li:hover > ul {
  display: block;
}

to be applied to an HTML structure like the following:

HTML
<div class="menu-bar">
  <ul>
    <li>
      <a href="example.html">Menu</a>
      <ul>
        <li>
          <a href="example.html">Link</a>
        </li>
        <li>
          <a class="menu-nav" href="example.html">Submenu</a>
          <ul>
            <li>
              <a class="menu-nav" href="example.html">Submenu</a>
              <ul>
                <li><a href="example.html">Link</a></li>
                <li><a href="example.html">Link</a></li>
                <li><a href="example.html">Link</a></li>
                <li><a href="example.html">Link</a></li>
              </ul>
            </li>
            <li><a href="example.html">Link</a></li>
          </ul>
        </li>
      </ul>
    </li>
  </ul>
</div>

See our complete CSS-based dropdown menu example for a possible cue.

Gallery with full-size images and previews

You can use the :hover pseudo-class in order to build an image gallery with full-size images shown only when mouse goes over previews. See this demo for a possible cue.

Note: For an analogous effect, but based on the :checked pseudo-class (applied to hidden radioboxes), see this demo, taken from the En/CSS/:checked page.

Syntax  

CSS
:hover <a href="css/value_definition_syntax#curly_braces_(.7b_.7d)" title="Curly braces">{</a> <var>style properties</var> <a href="css/value_definition_syntax#curly_braces_(.7b_.7d)" title="Curly braces">}</a>

Description  

The :hover CSS pseudo-class matches when the user designates an element with a pointing device, but does not necessarily activate it. This style may be overridden by any other link-related pseudo-classes, that is :link, :visited, and :active, appearing in subsequent rules. In order to style appropriately links, you need to put the :hover rule after the :link and :visited rules but before the :active one, as defined by the LVHA-order: :link:visited:hover:active.

The :hover pseudo-class can be applied to any pseudo-element.

Visual user agents, like Firefox, Internet Explorer, Safari, Opera or Chrome, apply the associated style when the cursor (mouse pointer) hovers over an element.

Usage Note: on touch screens :hover is problematic or impossible. Depending on the browser, the :hover pseudo-class might never match, or match only for a short moment after touching an element, or may continue to match even after the user has stopped touching and until the user touches another element. As touchscreen devices are very common, it is important for web developers not to have content be accessible only when hovering over it, as this content is more cumbersome or impossible for users of such devices to access.

Browser Compatibility  

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari
for <a> elements 0.2 1.0 (1.7 or earlier) 4.0 4.0 2.0.4 (419)
various bugs before
for all elements 0.2 1.0 (1.7 or earlier) 7.0 7.0 2.0.4 (419)
various bugs before
for pseudo-element ? 28 (28) ? ? ?
Feature Android Firefox Mobile (Gecko) IE Mobile Opera Mobile Safari Mobile
Basic support ? ? ? ? ?

In IE8-11, hovering over an element and then scrolling up/down without moving the pointer will leave the element in :hover state until the pointer is moved. See IE bug 926665.

In IE9 (and possibly earlier), if a <table> has a parent with a non-auto width and overflow-x: auto;, and the <table> has enough content to horizontally overflow its parent and there are :hover styles set on elements within the table, then hovering over said elements will cause the <table>'s height to increase. Here's a live demo that triggers the bug. One workaround for the bug is to set min-height: 0%; on the table's parent element (and the % unit must be specified; 0 and 0px don't work). There was a bug raised as jQuery ticket #10854, but it has been closed, because it is not considered a jQuery bug.

As of Safari Mobile for iOS 7.1.2, tapping a clickable element causes the element to enter the :hover state, and the element will remain in the :hover state until a different element has entered the :hover state.

See also:

Specifications  

Specification Status Comment
WHATWG HTML Living Standard
The definition of ':hover' in that specification.
Living Standard  
Selectors Level 4
The definition of ':hover' in that specification.
Working Draft Can be applied to any pseudo-element.
Selectors Level 3
The definition of ':hover' in that specification.
Recommendation No significant change.
CSS Level 2 (Revision 1)
The definition of ':hover' in that specification.
Recommendation Initial definition.

License

© 2016 Mozilla Contributors
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-us/docs/web/css/:hover

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