locale-code-helper

A lightweight TypeScript utility to extract language and country codes from IETF locale strings like en-US, fr-CA, etc.

• ✅ Zero dependencies
• ✅ Fully typed (TypeScript)
• ✅ ES Modules support only

📦 Installation

npm install locale-code-helper

ℹ️ This package uses native ES Modules.
Ensure your package.json includes "type": "module".

🚀 Usage

import {
  getLanguageFromLocale,
  getCountryFromLocale,
  isValidLocale,
  formatLocale,
  getLanguageName,
  getCountryName,
} from 'locale-code-helper';

getLanguageFromLocale('en-US'); // "en"
getCountryFromLocale('en-US');  // "US"
isValidLocale('ko-KR');         // true
formatLocale('fr-FR');          // "French (France)"
getLanguageName('ja-JP');       // "Japanese"
getCountryName('ja-JP');        // "Japan"

🔧 API

getLanguageFromLocale(locale: string): string

Extracts the language code from a locale string.
Example: "en-US" → "en"

getCountryFromLocale(locale: string): string

Extracts the country/region code from a locale string.
Example: "en-US" → "US"

isValidLocale(locale: string): boolean

Returns true if the input string is a valid BCP 47 locale
(e.g., "en", "en-US", "ko-KR"), otherwise false.

formatLocale(locale: string): string

Returns a formatted name combining language and country.
Example: "fr-FR" → "French (France)"

getLanguageName(locale: string): string

Returns the full name of the language based on the given locale.
Example: "ja-JP" → "Japanese"

getCountryName(locale: string): string

Returns the full name of the country or region based on the given locale.
Example: "ja-JP" → "Japan"

📄 License

MIT © 2025 Hyunjung Kim