i18next and React application localization in 3 steps

3 min readOct 1, 2020

How to start with i18n in ReactJS?

Thanks to that ReactJS is super popular library we got so many options. The most popular i18n libraries are i18next and yahoo/react-intl. Today I will show you how to integrate i18next into your ReactJS application.

Create a sample project

I will start with very beginning, and I will create sample app in ReactJS with TypeScript

yarn create react-app simplelocalize-i18next-example --template typescript

Install dependencies:

npm install --save react-i18next i18next i18next-http-backend i18next-browser-languagedetector

No we are ready to start!

Configuring i18next

I will create i18n.ts file where I will put whole i18next configuration, after that we will import this file in index.ts. My i18n.ts looks as following:

import i18n from 'i18next'
import Backend from 'i18next-http-backend'
import LanguageDetector from 'i18next-browser-languagedetector'
import { initReactI18next } from 'react-i18next'const projectToken = "5e13e3019cff4dc6abe36009445f0883";
const loadPath = `https://cdn.simplelocalize.io/${projectToken}/_latest/i18next/{{lng}}/{{ns}}/_index`;i18n
  .use(Backend)
  .use(LanguageDetector)
  .use (initReactI18next)
  .init({
    // default/fallback language 
    fallbackLng: 'en',
    ns: ["default"],
    defaultNS: "default",
    //detects and caches a cookie from the language provided
    detection: {
      order: ['queryString', 'cookie'],
      cache: ['cookie']
    },
    interpolation: {
      escapeValue: false
    },
    backend: {
      loadPath
    }
  })export default i18n;

Project `loadPath` variable

Create a SimpleLocalize.io project to get your unique loadPath variable. For this demo project you can use the loadPath from the example above!

Enable `i18next` in application

Configuration is completed when you import i18n.ts file in index.ts just by adding import './i18n'; Whole index.ts file should looks like this:

import React from 'react';
import ReactDOM from 'react-dom';
import './index.css';
import App from './App';
import './i18n'; // import i18next configuration (!!)ReactDOM.render (
  <React.StrictMode>
    <Suspense fallback={<div>Loading...</div>}>
        <App />
    </Suspense>
  </React.StrictMode>,
  document.getElementById('root')
);

We are done! i18next library is ready to use.

Using translations in the app

Now, let’s use translations, and create very simple web page.

Import `useTranslation` hook

To import the i18next hook we use the following code:

import {useTranslation} from "react-i18next";function App () {
  const {t, i18n} = useTranslation ();
  //...

The t variable is a function used to load translations for given key.

Using `t` in application code

t usage is very simple and clean:

t("USE_BUTTONS_BELOW")

in HTML, it would look like following:

<p>{t("USE_BUTTONS_BELOW")}</p>

Switching between language

Now it’s a time to add option to switch languages. I will use simple buttons without any fancy CSS styles. :) I added 3 buttons for English, Spanish and Polish language.

import React from "react";
import "./App.css";
import { useTranslation } from "react-i18next";function App() {
  const { t, i18n } = useTranslation();
  return (
    <div>
          <p>
            {t("USE_BUTTONS_BELOW")}
          </p>
          <button onClick={() => i18n.changeLanguage("en")}>English</button>
          <button onClick={() => i18n.changeLanguage("es")}>Spanish</button>
          <button onClick={() => i18n.changeLanguage("pl")}>Polish</button>
        </div>
  );
}export default App;