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String.prototype.toLowerCase() - JavaScript | MDN
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  4. Standard built-in objects
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  6. toLowerCase()
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String.prototype.toLowerCase()

Baseline Widely available

This feature is well established and works across many devices and browser versions. Its been available across browsers since July 2015.

The toLowerCase() method of String values returns this string converted to lower case.

In this article

Try it

const sentence = "The quick brown fox jumps over the lazy dog.";

console.log(sentence.toLowerCase());
// Expected output: "the quick brown fox jumps over the lazy dog."

Syntax

js
toLowerCase()

Parameters

None.

Return value

A new string representing the calling string converted to lower case.

Description

The toLowerCase() method returns the value of the string converted to lower case. toLowerCase() does not affect the value of the string str itself.

Examples

Using toLowerCase()

js
console.log("ALPHABET".toLowerCase()); // 'alphabet'

Specifications

Specification
ECMAScript 2027 LanguageSpecification
# sec-string.prototype.tolowercase

Browser compatibility

See also

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