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A CSS pseudo-element is a keyword added to a selector that lets you style a specific part of the selected element(s). For example, ::first-line can be used to style the first line of a paragraph.

In contrast to pseudo-elements, pseudo-classes can be used to style an element based on its state.


selector::pseudo-element {
  property: value;

You can use only one pseudo-element in a selector. It must appear after the simple selectors in the statement.

Note: As a rule, double colons (::) should be used instead of a single colon (:). This distinguishes pseudo-classes from pseudo-elements. However, since this distinction was not present in older versions of the W3C spec, most browsers support both syntaxes for the sake of compatibility. Note that ::selection must always start with double colons (::).

Index of pseudo-elements

Browser Lowest Version Support of
Internet Explorer 8.0 :pseudo-element
9.0 :pseudo-element ::pseudo-element
Firefox (Gecko) 1.0 (1.0) :pseudo-element
1.0 (1.5) :pseudo-element ::pseudo-element
Opera 4.0 :pseudo-element
7.0 :pseudo-element ::pseudo-element
Safari (WebKit) 1.0 (85) :pseudo-element ::pseudo-element