How to Change Mac System Language via Command Line

Polyglots, learners, and the bilingual often want to change their Mac system language for obvious reasons, but another less obvious situation can occur if you’re troubleshooting a Mac that either originates in another country, had the language changed at some point, or is just set to a different language.

Since it can be pretty challenging to navigate around in a language you don’t know at all or barely understand, it may be difficult to add and change the language in Mac OS X through System Preferences, and sometimes that easy approach is just downright impossible or inaccessible, perhaps because you’re reinstalling system software, or booted into Single User Mode for troubleshooting purposes.

But not to panic, you can also change the system language used on a Mac from the command line, handled entirely from the Terminal. This means you can either change the language directly from an active Terminal app, or even through ssh remotely if need be.

Changing the System Language in Mac OS X via Command Line languagesetup Tools

This works in all versions of Mac OS X, whether it’s a version called MacOS, Mac OS X, OS X, or BoggleTurkeyOS.

1. Launch Terminal if you have not done so already (or ssh if you’re doing this remotely)
2. Type the following command then hit return:

sudo languagesetup

3. Type the number which corresponds to the language you want to set the Mac system to (1 is for English) then hit the Return key for the language to be set*
4. Reboot the Mac from the command line or as usual from the Apple menu, it will now reboot and load with the language set to your choice

* The complete list of number codes plus the associate language is listed below, this should make it easier to navigate if you find yourself on a Mac set to a non-native language.

1) Use English for the main language
2) Utiliser le français comme langue principale
3) Deutsch als Standardsprache verwenden
4) 以简体中文作为主要语言
5) 以繁體中文作為主要語言
6) 主に日本語を使用する
7) Usar español como idioma principal
8) Usa l’italiano come lingua principale
9) Gebruik Nederlands als hoofdtaal
10) 주 언어로 한국어 사용
11) Usar português do Brasil como idioma principal
12) Usar o português europeu como idioma principal
13) Brug dansk som hovedsprog
14) Käytä pääkielenä suomea
15) Bruk norsk som hovedspråk
16) Använd svenska som huvudspråk
17) Сделать русский язык основным языком системы
18) Użyj polskiego jako języka głównego
19) Ana dil olarak Türkçe’yi kullan
20) استخدام اللغة العربية كلغة رئيسية
21) เลือกภาษาไทยเป็นภาษาหลัก
22) Vybrat češtinu jako hlavní jazyk
23) Magyar kiválasztása alapértelmezett nyelvként
24) Seleccioneu el català com a idioma principal
25) Odaberite hrvatski kao glavni jezik
26) Επιλέξτε Ελληνικά ως την κύρια γλώσσα
27) בחר/י עברית כשפה ראשית
28) Selectați româna ca limbă principală
29) Vybrať slovenčinu ako hlavný jazyk
30) Вибрати українську основною мовою
31) Gunakan Bahasa Indonesia sebagai bahasa utama
32) Gunakan Bahasa Melayu untuk bahasa utama
33) Sử dụng Tiếng Việt làm ngôn ngữ chính
34) Utilizar español de México como el idioma principal
q) Quit

This is obviously more technical than adding a new language or changing the MacOS system language it from the preferences panel in Mac OS X, but it can be extremely helpful for some unique troubleshooting situations. Remember you can also switch the keyboard language quickly with a keystroke if you frequently switch languages that are being typed as well.