🌍  react-native-localize

A toolbox for your React Native app localization.

Support

This library follows the React Native releases support policy.
It is supporting the latest version, and the two previous minor series.

Setup

$ npm install --save react-native-localize
# --- or ---
$ yarn add react-native-localize

Don't forget to run pod install after that !

Expo plugin

If you're using Expo, you can specify the supported locales in your app.json or app.config.js using the config plugin. This enables Android 13+ and iOS to display the available locales in the system settings, allowing users to select their preferred language for your app.

import type { ConfigContext, ExpoConfig } from "expo/config";
import localize from "react-native-localize/expo"; // use `require` in app.config.js

export default ({ config }: ConfigContext): ExpoConfig => ({
  plugins: [
    localize({
      locales: ["en", "fr"], // or { android: ["en"], ios: ["en", "fr"] }
    }),
  ],
});

{
  "expo": {
    "plugins": [
      [
        "react-native-localize",
        {
          "locales": ["en", "fr"], // or { android: ["en"], ios: ["en", "fr"] }
        },
      ],
    ],
  },
}

Web support

This package supports react-native-web. Follow their official guide to configure webpack.

Basic usage example

import { getCurrencies, getLocales } from "react-native-localize";

console.log(getLocales());
console.log(getCurrencies());

API

getCalendar()

Returns the user preferred calendar format.

Method type

type getCalendar = () =>
  | "gregorian"
  | "buddhist"
  | "coptic"
  | "ethiopic"
  | "ethiopic-amete-alem"
  | "hebrew"
  | "indian"
  | "islamic"
  | "islamic-umm-al-qura"
  | "islamic-civil"
  | "islamic-tabular"
  | "iso8601"
  | "japanese"
  | "persian";

Usage example

import { getCalendar } from "react-native-localize";

console.log(getCalendar());
// -> "gregorian"

getCountry()

Returns the user current country code (based on its device locale, not on its position).

Method type

type getCountry = () => string;

Usage example

import { getCountry } from "react-native-localize";

console.log(getCountry());
// -> "FR"

Note

Devices using Latin American regional settings will return "UN" instead of "419", as the latter is not a standard country code.

getCurrencies()

Returns the user preferred currency codes, in order.

Method type

type getCurrencies = () => string[];

Usage example

import { getCurrencies } from "react-native-localize";

console.log(getCurrencies());
// -> ["EUR", "GBP", "USD"]

getLocales()

Returns the user preferred locales, in order.

Method type

type getLocales = () => Array<{
  languageCode: string;
  scriptCode?: string;
  countryCode: string;
  languageTag: string;
  isRTL: boolean;
}>;

Usage example

import { getLocales } from "react-native-localize";

console.log(getLocales());
/* -> [
  { countryCode: "GB", languageTag: "en-GB", languageCode: "en", isRTL: false },
  { countryCode: "US", languageTag: "en-US", languageCode: "en", isRTL: false },
  { countryCode: "FR", languageTag: "fr-FR", languageCode: "fr", isRTL: false },
] */

getNumberFormatSettings()

Returns number formatting settings.

Method type

type getNumberFormatSettings = () => {
  decimalSeparator: string;
  groupingSeparator: string;
};

Usage example

import { getNumberFormatSettings } from "react-native-localize";

console.log(getNumberFormatSettings());
/* -> {
  decimalSeparator: ".",
  groupingSeparator: ",",
} */

getTemperatureUnit()

Returns the user preferred temperature unit.

Method type

type getTemperatureUnit = () => "celsius" | "fahrenheit";

Usage example

import { getTemperatureUnit } from "react-native-localize";

console.log(getTemperatureUnit());
// -> "celsius"

getTimeZone()

Returns the user preferred timezone (based on its device settings, not on its position).

Method type

type getTimeZone = () => string;

Usage example

import { getTimeZone } from "react-native-localize";

console.log(getTimeZone());
// -> "Europe/Paris"

uses24HourClock()

Returns true if the user prefers 24h clock format, false if they prefer 12h clock format.

Method type

type uses24HourClock = () => boolean;

Usage example

import { uses24HourClock } from "react-native-localize";

console.log(uses24HourClock());
// -> true

usesMetricSystem()

Returns true if the user prefers metric measure system, false if they prefer imperial.

Method type

type usesMetricSystem = () => boolean;

Usage example

import { usesMetricSystem } from "react-native-localize";

console.log(usesMetricSystem());
// -> true

usesAutoDateAndTime()

Tells if the automatic date & time setting is enabled on the phone. Android only

Method type

type usesAutoDateAndTime = () => boolean | undefined;

Usage example

import { usesAutoDateAndTime } from "react-native-localize";

console.log(usesAutoDateAndTime()); // true or false

usesAutoTimeZone()

Tells if the automatic time zone setting is enabled on the phone. Android only

Method type

type usesAutoTimeZone = () => boolean | undefined;

Usage example

import { usesAutoTimeZone } from "react-native-localize";

console.log(usesAutoTimeZone());

findBestLanguageTag()

Returns the best language tag possible and its reading direction. Useful to pick the best translation available.

[!NOTE]

It respects the user preferred languages list order (see explanations).

Method type

type findBestLanguageTag = (
  languageTags: string[],
) => { languageTag: string; isRTL: boolean } | undefined;

Usage example

import { findBestLanguageTag } from "react-native-localize";

console.log(findBestLanguageTag(["en-US", "en", "fr"]));
// -> { languageTag: "en-US", isRTL: false }

openAppLanguageSettings()

Opens the app language settings.

[!WARNING]

This feature is available only on Android 13+ and require configuring your app's supported locales.

Method type

type openAppLanguageSettings = () => Promise<void>;

Usage example

import { openAppLanguageSettings } from "react-native-localize";

openAppLanguageSettings("application").catch((error) => {
  console.warn("Cannot open app language settings", error);
});

Server-side rendering

On the client, react-native-localize uses navigator.languages. During SSR, it gets language preferences from the server via the parsed Accept-Language header.

1. Wrap your app with ServerLanguagesProvider

On the server, wrap your app with ServerLanguagesProvider and pass the user's languages:

import accepts from "accepts";
import { ServerLanguagesProvider } from "react-native-localize";

// parse the Accept-Language header; any approach returning string[] is fine
const languages = accepts(request).languages();

const html = renderToString(
  <ServerLanguagesProvider value={languages}>
    <App />
  </ServerLanguagesProvider>,
);

2. Use the useLocalize hook in your components

In your components, use the useLocalize hook instead of calling the API methods directly:

import { useLocalize } from "react-native-localize";

const App = () => {
  const { getCountry } = useLocalize();
  return <Text>Country: {getCountry()}</Text>;
};

Examples with @formatjs/intl

Browse the files in the /example directory.

How to update supported localizations (iOS)

You can add / remove supported localizations in your Xcode project infos:

How to test your code

Because it's a native module, you need to mock this package.
The package provides a default mock you may import in your __mocks__ directory:

// __mocks__/react-native-localize.ts
export * from "react-native-localize/mock"; // or "react-native-localize/mock/jest"

Sponsors

This module is provided as is, I work on it in my free time.

If you or your company uses it in a production app, consider sponsoring this project 💰. You also can contact me for premium enterprise support: help with issues, prioritize bugfixes, feature requests, etc.