The type read-only property of the CSSPseudoElement interface returns the type of the pseudo-element as a string, represented in the form of a CSS selector.

A string containing one of the following values:

• "::before"
• "::after"
• "::marker"

The example below demonstrates the relationship between CSSPseudoElement.type and Element.pseudo():

const myElement = document.querySelector("q");
const mySelector = "::after";
const cssPseudoElement = myElement.pseudo(mySelector);
const typeOfPseudoElement = cssPseudoElement.type;

console.log(mySelector === typeOfPseudoElement); // Outputs true

• Element.pseudo()
• Index of standard pseudo-elements