Cover image for i18-web: Tool for String Externalization and Internationalizing the Web

i18-web: Tool for String Externalization and Internationalizing the Web

atapas profile image Tapas Adhikary Originally published at blog.greenroots.info ・3 min read


i18n-web is a simple tool helps in externalizing the strings in a JavaScript based Application such that, Internationalization(i18n) can be achieved easily. It has the additional capability of parameterizing the strings to get the dynamic content Internationalized.


  • Using yarn
 yarn add i18n-web
  • Using npm
 npm install i18n-web


Before we go over the usage of the tool, let us understand some of the fundamentals at a high level.

What is String Externalization

String Externalization means, instead of writing the user(or customer) facing strings in source files(.html, .js, .java etc), we keep them in an external file like .properties, .json etc and load from there. This is to help Internationalization (i18n).

What is Internationalization aka i18n

In Software, Internationalization (i18n) is the process to support various local languages like, English(en), Spanish(es), German(de) etc.

In i18n, 18 stands for the number of letters between the first i and the last n in the word internationalization, a usage coined at Digital Equipment Corporation.

All the browsers come with the in-built support of languages which can be used to identify the local language to support for the application.

How String Externalization help in Internationalization of the Web Applications

A Web Application may have the need of supporting multiple languages based on the targeted users. If the Application Strings are Externalized outside of the source files, it is easy and flexible to support Internationalization(i18n).

Lets consider, all the application strings are in a file called en.json and this file can be loaded into the application to retrieve the strings when the app is running in English Language.

    'username': 'User Name',
    'password': 'Password',
    'hasBlog': '{0} has a blog named, {1}. This is on {2}.'

Now there could be equivalent es.json file which can be loaded into the application when browser supported language is Spanish instead of English.

    'username': 'Nombre de usuario',
    'password': 'Contraseña',
    'hasBlog': '{0} tiene un blog llamado {1}. Esto está en {2}.'

i18n-web Usage

Basic Setup and Structure

The tool i18n-web helps in externalizing the string and thus, internationalizing your web app with few quick and easy steps.

  • Create a folder called i18n at the same level of node_modules folder of your app.
  • Create en.js, es.js, de.js etc file to contain your application specific strings externalized. You must add all required language .js files that your app would support.

Here is an example of the en.js and es.js file.

  • en.js
   // en.js
   const en = {
      'username': 'User Name',
      'password': 'Password',
      'hasBlog': '{0} has a blog named, {1}. This is on {2}.'

     export { en };
  • es.js
    // es.js
    const es = {
        'username': 'Nombre de usuario',
        'password': 'Contraseña',
        'hasBlog': '{0} tiene un blog llamado {1}. Esto está en {2}.'

    export { es };
  • Create another file called, index.js where you can aggregate the all modules and export together like this:
   export { en } from './en.js';
   export { es } from './es.js';

Example Directory Structure:

    └── i18n
        └── en.js
        └── es.js
        └── de.js
        └── fr.js
        └── index.js                
    └── node_modules                    

Using it in the UI Code

  • In your UI Code, import it as,
   import i18n from 'i18n-web';
  • Use it like:
    // When no parameters. Just Key is passed

    // Output: 

    // 'User Name' for English 

    // 'Nombre de usuario' for Spanish 

    // With parameters.
    const params = ['Tapas', 'greenroos', 'JavaScript'];
    let hasBlog = i18n('hasBlog', ...params);

    // Output: 

    // 'Tapas has a blog named, greenroots. This is on JavaScript.' for English and 

    // 'Tapas tiene un blog llamado greenroots. Esto está en JavaScript.' for Spanish 



Tested With following Frameworks and Libraries



Here are the links to some use resources,

That's all for now. Please use i18n-web package with your web application. Feel free to spread the words about i18n-web and you are welcome to Contribute to the project.

This article was originally published in my GreenRoots Blog. You can follow me on twitter(@tapasadhikary).

Are you waiting to Publish your first npm? Here is my article can help you with it, Build, Test and Publish your NPM, I just did it in few minutes!


Editor guide