Skip to content

The String toLocaleUpperCase() method

Find out all about the JavaScript toLocaleUpperCase() method of a string

Returns a new string with the uppercase transformation of the original string, according to the locale case mappings.

The first parameter represents the locale, but it’s optional (and if omitted, the current locale is used):

'Testing'.toLocaleUpperCase() //'TESTING'
'Testing'.toLocaleUpperCase('it') //'TESTING'
'Testing'.toLocaleUpperCase('tr') //'TESTİNG'

Similar to the toUpperCase() method, except that does not take locales into consideration.

→ Get my JavaScript Beginner's Handbook

I wrote 17 books to help you become a better developer, download them all at $0 cost by joining my newsletter

  • C Handbook
  • Command Line Handbook
  • CSS Handbook
  • Express Handbook
  • Git Cheat Sheet
  • Go Handbook
  • HTML Handbook
  • JS Handbook
  • Laravel Handbook
  • Next.js Handbook
  • Node.js Handbook
  • PHP Handbook
  • Python Handbook
  • React Handbook
  • SQL Handbook
  • Svelte Handbook
  • Swift Handbook

JOIN MY CODING BOOTCAMP, an amazing cohort course that will be a huge step up in your coding career - covering React, Next.js - next edition February 2025

Bootcamp 2025

Join the waiting list