JavaScript (ES2026) reference · String Methods

JavaScript String toUpperCase() Method

Return the string converted to uppercase letters. Use toLocaleUpperCase() for language-specific rules.

JavaScript (ES2026) Since ES1

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Syntax

string.toUpperCase()

A new string.

UppercaseTry it yourself

console.log("ready camel".toUpperCase());

Output

READY CAMEL

Capitalize the first letterTry it yourself

const capitalize = (s) => s.charAt(0).toUpperCase() + s.slice(1);
console.log(capitalize("javaScript"));

Output

JavaScript

Version	Change
JavaScript ES1	Added

string.toLowerCase() · Return the string converted to lowercase. Use it for case-insensitive comparisons.
string.toLocaleUpperCase() · Convert to uppercase using a language's rules, for example Turkish or German special cases.
JavaScript Strings · tutorial
JavaScript String Methods · tutorial