The content
CSS property replaces an element with a generated value. Objects inserted using the content
property are anonymous replaced elements.
/* Keywords that cannot be combined with other values */ content: normal; content: none; /* <image> values */ content: url("http://www.example.com/test.png"); content: linear-gradient(#e66465, #9198e5); /* alt text for generated content, added in the Level 3 specification */ content: url("http://www.example.com/test.png") / "This is the alt text"; /* values below can only be applied to generated content using ::before and ::after */ /* <string> value */ content: "prefix"; /* <counter> values, optionally with <list-style-type> */ content: counter(chapter_counter); content: counter(chapter_counter, upper-roman); content: counters(section_counter, "."); content: counters(section_counter, ".", decimal-leading-zero); /* attr() value linked to the HTML attribute value */ content: attr(value string); /* Language- and position-dependent keywords */ content: open-quote; content: close-quote; content: no-open-quote; content: no-close-quote; /* Except for normal and none, several values can be used simultaneously */ content: open-quote counter(chapter_counter); /* Global values */ content: inherit; content: initial; content: unset;
Syntax
Values
none
- The pseudo-element is not generated.
normal
- Computes to
none
for the::before
and::after
pseudo-elements. <string>
- Specifies the "alt text" for the element. This value can be any number of text characters. Non-Latin characters must be encoded using their Unicode escape sequences: for example,
\000A9
represents the copyright symbol. <image>
- An
<image>
, denoted by the<url>
or<gradient>
data type, or part of the webpage, defined by theelement()
function, denoting the content to display. <counter>
- The value of a CSS counter, generally a number produced by computations defined by
<counter-reset>
and<counter-increment>
properies. It can be displayed using either thecounter
orcounters
function. The
counter
function has two forms: 'counter(name
)' or 'counter(name
, style)'. The generated text is the value of the innermost counter of the given name in scope at the given pseudo-element. It is formatted in the specified<list-style-type>
(decimal
by default).The
counters
function also has two forms: 'counters(name
,string
)' or 'counters(name
,string
,style
)'. The generated text is the value of all counters with the given name in scope at the given pseudo-element, from outermost to innermost, separated by the specified string. The counters are rendered in the indicated<list-style-type>
(decimal
by default).attr(x)
- The value of the element's attribute
x
as a string. If there is no attributex
, an empty string is returned. The case-sensitivity of attribute names depends on the document language. open-quote
|close-quote
- These values are replaced by the appropriate string from the
quotes
property. no-open-quote
|no-close-quote
- Introduces no content, but increments (decrements) the level of nesting for quotes.
Accessibility concerns
CSS-generated content is not included in the DOM. Because of this, it will not be represented in the accessibility tree and certain assistive technology/browser combinations will not announce it. If the content conveys information that is critical to understanding the page's purpose, it is better to include it in the main document.
- Accessibility support for CSS generated content – Tink
- Explanation of WCAG, Guideline 1.3 – MDN
- Understanding Success Criterion 1.3.1 | W3C Understanding WCAG 2.0
Formal definition
Initial value | normal
|
Applies to | ::before and ::after pseudo-elements
|
Inherited | no |
Computed value | On elements, always computes to normal . On ::before and ::after , if normal is specified, computes to none . Otherwise, for URI values, the absolute URI; for attr() values, the resulting string; for other keywords, as specified.
|
Animation type | discrete |
Formal syntax
normal | none | [ <content-replacement> | <content-list> ] [/ <string> ]?where <content-replacement> = <image><content-list> = [ <string> | contents | <image> | <quote> | <target> | <leader()> ]+where <image> = <url> | <image()> | <image-set()> | <element()> | <paint()> | <cross-fade()> | <gradient><quote> = open-quote | close-quote | no-open-quote | no-close-quote<target> = <target-counter()> | <target-counters()> | <target-text()><leader()> = leader( <leader-type> )where <image()> = image( <image-tags>? [ <image-src>? , <color>? ]! )<image-set()> = image-set( <image-set-option># )<element()> = element( <id-selector> )<paint()> = paint( <ident>, <declaration-value>? )<cross-fade()> = cross-fade( <cf-mixing-image> , <cf-final-image>? )<gradient> = <linear-gradient()> | <repeating-linear-gradient()> | <radial-gradient()> | <repeating-radial-gradient()> | <conic-gradient()><target-counter()> = target-counter( [ <string> | <url> ] , <custom-ident> , <counter-style>? )<target-counters()> = target-counters( [ <string> | <url> ] , <custom-ident> , <string> , <counter-style>? )<target-text()> = target-text( [ <string> | <url> ] , [ content | before | after | first-letter ]? )<leader-type> = dotted | solid | space | <string>where <image-tags> = ltr | rtl<image-src> = <url> | <string><color> = <rgb()> | <rgba()> | <hsl()> | <hsla()> | <hex-color> | <named-color> | currentcolor | <deprecated-system-color><image-set-option> = [ <image> | <string> ] <resolution><id-selector> = <hash-token><cf-mixing-image> = <percentage>? && <image><cf-final-image> = <image> | <color><linear-gradient()> = linear-gradient( [ <angle> | to <side-or-corner> ]? , <color-stop-list> )<repeating-linear-gradient()> = repeating-linear-gradient( [ <angle> | to <side-or-corner> ]? , <color-stop-list> )<radial-gradient()> = radial-gradient( [ <ending-shape> || <size> ]? [ at <position> ]? , <color-stop-list> )<repeating-radial-gradient()> = repeating-radial-gradient( [ <ending-shape> || <size> ]? [ at <position> ]? , <color-stop-list> )<conic-gradient()> = conic-gradient( [ from <angle> ]? [ at <position> ]?, <angular-color-stop-list> )<counter-style> = <counter-style-name> | symbols()where <rgb()> = rgb( <percentage>{3} [ / <alpha-value> ]? ) | rgb( <number>{3} [ / <alpha-value> ]? ) | rgb( <percentage>#{3} , <alpha-value>? ) | rgb( <number>#{3} , <alpha-value>? )<rgba()> = rgba( <percentage>{3} [ / <alpha-value> ]? ) | rgba( <number>{3} [ / <alpha-value> ]? ) | rgba( <percentage>#{3} , <alpha-value>? ) | rgba( <number>#{3} , <alpha-value>? )<hsl()> = hsl( <hue> <percentage> <percentage> [ / <alpha-value> ]? ) | hsl( <hue>, <percentage>, <percentage>, <alpha-value>? )<hsla()> = hsla( <hue> <percentage> <percentage> [ / <alpha-value> ]? ) | hsla( <hue>, <percentage>, <percentage>, <alpha-value>? )<side-or-corner> = [ left | right ] || [ top | bottom ]<color-stop-list> = [ <linear-color-stop> [, <linear-color-hint>]? ]# , <linear-color-stop><ending-shape> = circle | ellipse<size> = closest-side | farthest-side | closest-corner | farthest-corner | <length> | <length-percentage>{2}<position> = [ [ left | center | right ] || [ top | center | bottom ] | [ left | center | right | <length-percentage> ] [ top | center | bottom | <length-percentage> ]? | [ [ left | right ] <length-percentage> ] && [ [ top | bottom ] <length-percentage> ] ]<angular-color-stop-list> = [ <angular-color-stop> [, <angular-color-hint>]? ]# , <angular-color-stop><counter-style-name> = <custom-ident>where <alpha-value> = <number> | <percentage><hue> = <number> | <angle><linear-color-stop> = <color> <color-stop-length>?<linear-color-hint> = <length-percentage><length-percentage> = <length> | <percentage><angular-color-stop> = <color> && <color-stop-angle>?<angular-color-hint> = <angle-percentage>where <color-stop-length> = <length-percentage>{1,2}<color-stop-angle> = <angle-percentage>{1,2}<angle-percentage> = <angle> | <percentage>
Examples
Headings and quotes
This example inserts quotation marks around quotes, and adds the word "Chapter" before headings.
HTML
<h1>5</h1>
<p>According to Sir Tim Berners-Lee,
<q cite="http://www.w3.org/People/Berners-Lee/FAQ.html#Internet">I was
lucky enough to invent the Web at the time when the Internet
already existed - and had for a decade and a half.</q>
We must understand that there is nothing fundamentally wrong
with building on the contributions of others.
</p>
<h1>6</h1>
<p>According to the Mozilla Manifesto,
<q cite="http://www.mozilla.org/en-US/about/manifesto/">Individuals
must have the ability to shape the Internet and
their own experiences on the Internet.</q>
Therefore, we can infer that contributing to the open web
can protect our own individual experiences on it.
</p>
CSS
q {
color: blue;
}
q::before {
content: open-quote;
}
q::after {
content: close-quote;
}
h1::before {
content: "Chapter "; /* The trailing space creates separation
between the added content and the
rest of the content */
}
Result
Image combined with text
This example inserts an image before the link. If the image is not found, it inserts text instead.
HTML
<a href="http://www.mozilla.org/en-US/">Mozilla Home Page</a>
CSS
a::before {
content: url("https://mozorg.cdn.mozilla.net/media/img/favicon.ico") / " MOZILLA: ";
font: x-small Arial, sans-serif;
color: gray;
}
Result
Targeting classes
This example inserts additional text after special items in a list.
HTML
<h2>Paperback Best Sellers</h2>
<ol>
<li>Political Thriller</li>
<li class="new-entry">Halloween Stories</li>
<li>My Biography</li>
<li class="new-entry">Vampire Romance</li>
</ol>
CSS
.new-entry::after {
content: " New!"; /* The leading space creates separation
between the added content and the
rest of the content */
color: red;
}
Result
Images and element attributes
This example inserts an image before each link, and adds its id
attribute after.
HTML
<ul>
<li><a id="moz" href="http://www.mozilla.org/">
Mozilla Home Page</a></li>
<li><a id="mdn" href="https://developer.mozilla.org/">
Mozilla Developer Network</a></li>
</ul>
CSS
a {
text-decoration: none;
border-bottom: 3px dotted navy;
}
a::after {
content: " (" attr(id) ")";
}
#moz::before {
content: url("https://mozorg.cdn.mozilla.net/media/img/favicon.ico");
}
#mdn::before {
content: url("https://mdn.mozillademos.org/files/7691/mdn-favicon16.png");
}
li {
margin: 1em;
}
Result
Element replacement
This example replaces an element's content with an image. You can replace the contents of an element with either a <url>
or an <image>
value. Content added with ::before
or ::after
will not be generated as the contents of the element have been replaced.
HTML
<div id="replaced">Mozilla</div>
CSS
#replaced {
content: url("https://mdn.mozillademos.org/files/12668/MDN.svg");
}
#replaced::after { /* will not show if element replacement is supported */
content: " (" attr(id) ")";
}
Result
Specifications
Specification | Status | Comment |
---|---|---|
CSS Generated Content Module Level 3The definition of 'content' in that specification. | Working Draft | Adds support for alt-text |
CSS Level 2 (Revision 1)The definition of 'content' in that specification. | Recommendation | Initial definition |
Browser compatibility
The compatibility table on this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request.
Update compatibility data on GitHub
Desktop | Mobile | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
content
|
Chrome
Full support 1 |
Edge
Full support 12 |
Firefox
Full support 1 |
IE
Full support 8 |
Opera
Full support 4 |
Safari
Full support 1 |
WebView Android
Full support 1 |
Chrome Android
Full support 18 |
Firefox Android
Full support 4 |
Opera Android
Full support 10.1 |
Safari iOS
Full support 1 |
Samsung Internet Android
Full support 1.0 |
Alternative text after /
|
Chrome
Full support 77 |
Edge
Full support 79 |
Firefox
No support No |
IE
No support No |
Opera
Full support 64 |
Safari
No support No |
WebView Android
Full support 77 |
Chrome Android
Full support 77 |
Firefox Android
No support No |
Opera Android
Full support 55 |
Safari iOS
No support No |
Samsung Internet Android
Full support 12.0 |
Element replacement | Chrome
Full support 28 |
Edge
Full support 79 |
Firefox
Full support 63 |
IE
No support No |
Opera
Full support 7 |
Safari
Full support 9 |
WebView Android
Full support ≤37 |
Chrome Android
Full support 28 |
Firefox Android
Full support 63 |
Opera Android
Full support 10.1 |
Safari iOS
Full support 9 |
Samsung Internet Android
Full support 1.5 |
url()
|
Chrome
Full support 1 |
Edge
Full support 12 |
Firefox
Full support 1 |
IE
Full support 8 |
Opera
Full support 7 |
Safari
Full support 1 |
WebView Android
Full support 37 |
Chrome Android
Full support 18 |
Firefox Android
Full support 4 |
Opera Android
Full support 14 |
Safari iOS
Full support 1 |
Samsung Internet Android
Full support 1.0 |
Legend
- Full support
- Full support
- No support
- No support
See also
content by Mozilla Contributors is licensed under CC-BY-SA 2.5.