The CSS attribute selector matches elements based on the presence or value of a given attribute.

/* <a> elements with a title attribute */
a[title] {
  color: purple;
}

/* <a> elements with an href matching "https://example.org" */
a[href="https://example.org"] {
  color: green;
}

/* <a> elements with an href containing "example" */
a[href*="example"] {
  font-size: 2em;
}

/* <a> elements with an href ending ".org" */
a[href$=".org"] {
  font-style: italic;
}
[attr]
Represents an element with an attribute name of attr.
[attr=value]
Represents an element with an attribute name of attr whose value is exactly value.
[attr~=value]
Represents an element with an attribute name of attr whose value is a whitespace-separated list of words, one of which is exactly value.
[attr|=value]
Represents an element with an attribute name of attr whose value can be exactly value or can begin with value immediately followed by a hyphen, - (U+002D). It is often used for language subcode matches.
[attr^=value]
Represents an element with an attribute name of attr whose value is prefixed (preceded) by value.
[attr$=value]
Represents an element with an attribute name of attr whose value is suffixed (followed) by value.
[attr*=value]
Represents an element with an attribute name of attr whose value contains at least one occurrence of value within the string.
[attr operator value i]
Adding an i (or I) before the closing bracket causes the value to be compared case-insensitively (for characters within the ASCII range).

Examples

CSS

a {
  color: blue;
}

/* Internal links, beginning with "#" */
a[href^="#"] {
  background-color: gold;
}

/* Links with "example" anywhere in the URL */
a[href*="example"] {
  background-color: silver;
}

/* Links with "insensitive" anywhere in the URL,
   regardless of capitalization */
a[href*="insensitive" i] {
  color: cyan;
}

/* Links that end in ".org" */
a[href$=".org"] {
  color: red;
}

HTML

<ul>
  <li><a href="#internal">Internal link</a></li>
  <li><a href="http://example.com">Example link</a></li>
  <li><a href="#InSensitive">Insensitive internal link</a></li>
  <li><a href="http://example.org">Example org link</a></li>
</ul>

Result

Languages

CSS

/* All divs with a `lang` attribute are bold. */
div[lang] {
  font-weight: bold;
}

/* All divs in US English are blue. */
div[lang~="en-us"] {
  color: blue;
}

/* All divs in Portuguese are green. */
div[lang="pt"] {
  color: green;
}

/* All divs in Chinese are red, whether
   simplified (zh-CN) or traditional (zh-TW). */
div[lang|="zh"] {
  color: red;
}

/* All divs with a Traditional Chinese
   `data-lang` are purple. */
/* Note: You could also use hyphenated attributes
   without double quotes */ 
div[data-lang="zh-TW"] {
  color: purple;
}

HTML

<div lang="en-us en-gb en-au en-nz">Hello World!</div>
<div lang="pt">Olá Mundo!</div>
<div lang="zh-CN">世界您好!</div>
<div lang="zh-TW">世界您好!</div>
<div data-lang="zh-TW">?世界您好!</div>

Result

Specifications

Specification Status Comment
Selectors Level 4
The definition of 'attribute selectors' in that specification.
Working Draft Adds modifier for ASCII case-insensitive attribute value selection
Selectors Level 3
The definition of 'attribute selectors' in that specification.
Recommendation  
CSS Level 2 (Revision 1)
The definition of 'attribute selectors' in that specification.
Recommendation Initial definition

Browser compatibility

FeatureChromeEdgeFirefoxInternet ExplorerOperaSafari
Basic support1121793
Case-insensitive modifier (i)49 No47 No369
FeatureAndroid webviewChrome for AndroidEdge mobileFirefox for AndroidIE mobileOpera AndroidiOS Safari
Basic support Yes Yes Yes4 Yes Yes Yes
Case-insensitive modifier (i)4949 No47 No Yes Yes