counter()

The counter() CSS function returns a string representing the current value of the named counter, if there is one.

The counter() function is generally used within pseudo-element through the content property but, theoretically, it can be used wherever a <string> value is supported.

Try it

Syntax

css
/* Simple usage */
counter(countername);

/* changing the counter display */
counter(countername, upper-roman)

Counters have no visible effect by themselves. The counter() and counters() functions are what make counters useful by returning developer-defined strings (or images).

Values

The counter() function accepts up to two parameters. The first parameter is the <counter-name>. The optional second parameter is the <counter-style>.

<counter-name>

A <custom-ident> identifying the counter, which is the same case-sensitive name used with the counter-reset and counter-increment property values. The counter name cannot start with two dashes and can't be none, unset, initial, or inherit.

<counter-style>

A <list-style-type> name, <@counter-style> name or symbols() function, where a counter style name is a numeric, alphabetic, or symbolic simple predefined counter style, a complex longhand east Asian or Ethiopic predefined counter style, or other predefined counter style. If omitted, the counter-style defaults to decimal.

Note: To join the counter values when nesting counters, use the counters() function, which provides an additional <string> parameter.

Formal syntax

<counter()> = 
counter( <counter-name> , <counter-style>? )

<counter-style> =
<counter-style-name> |
<symbols()>

<symbols()> =
symbols( <symbols-type>? [ <string> | <image> ]+ )

<symbols-type> =
cyclic |
numeric |
alphabetic |
symbolic |
fixed

<image> =
<url> |
<gradient>

<url> =
<url()> |
<src()>

<url()> =
url( <string> <url-modifier>* ) |
<url-token>

<src()> =
src( <string> <url-modifier>* )

Examples

lower-roman compared to lower-alpha

In this example, we display a counter using lower-roman and lower-alpha list styles.

HTML

html
<ol>
  <li></li>
  <li></li>
  <li></li>
</ol>

CSS

css
ol {
  counter-reset: count;
}
li {
  counter-increment: count;
}
li::after {
  content:
    "[" counter(count, lower-roman) "] == ["
    counter(count, lower-alpha) "]";
}

Result

Displaying a counter using three styles

In this example, we use the counter() function three times.

HTML

html
<ol>
  <li></li>
  <li></li>
  <li></li>
</ol>

CSS

We include the counter() function with three different counter styles, including the default decimal value. We've added padding to the list to provide space for the long ::marker string.

css
ol {
  counter-reset: listCounter;
  padding-left: 5em;
}
li {
  counter-increment: listCounter;
}
li::marker {
  content:
    "Item #" counter(listCounter) " is: ";
}
li::after {
  content:
    "[" counter(listCounter, decimal-leading-zero) "] == ["
    counter(listCounter, upper-roman) "]";
}

Result

Specifications

Specification
CSS Lists and Counters Module Level 3
# counter-functions

Browser compatibility

BCD tables only load in the browser

See also