Element.classList

The Element.classList is a read-only property that returns a live DOMTokenList collection of the class attributes of the element. This can then be used to manipulate the class list.

Using classList is a convenient alternative to accessing an element's list of classes as a space-delimited string via element.className.

Value

A DOMTokenList representing the contents of the element's class attribute. If the class attribute is not set or empty, it returns an empty DOMTokenList, i.e. a DOMTokenList with the length property equal to 0.

Although the classList property itself is read-only, you can modify its associated DOMTokenList using the add(), remove(), replace(), and toggle() methods.

Examples

const div = document.createElement('div');
div.className = 'foo';

// our starting state: <div class="foo"></div>
console.log(div.outerHTML);

// use the classList API to remove and add classes
div.classList.remove("foo");
div.classList.add("anotherclass");

// <div class="anotherclass"></div>
console.log(div.outerHTML);

// if visible is set remove it, otherwise add it
div.classList.toggle("visible");

// add/remove visible, depending on test conditional, i less than 10
div.classList.toggle("visible", i < 10 );

console.log(div.classList.contains("foo"));

// add or remove multiple classes
div.classList.add("foo", "bar", "baz");
div.classList.remove("foo", "bar", "baz");

// add or remove multiple classes using spread syntax
const cls = ["foo", "bar"];
div.classList.add(...cls);
div.classList.remove(...cls);

// replace class "foo" with class "bar"
div.classList.replace("foo", "bar");

Note: Versions of Firefox before 26 do not implement the use of several arguments in the add/remove/toggle methods. See https://bugzilla.mozilla.org/show_bug.cgi?id=814014

Specifications

Specification
DOM Standard # ref-for-dom-element-classlist①

Browser compatibility

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