JavaScript i18n Libraries

Updated May 17, 2023#javascript#libs#lists

Internationalization (i18n) is the design and development of a product, application or document content that enables easy localization for target audiences that vary in culture, region, or language.

Each language has different names for the days of the week and the months of the year, they also have different expectations for the structure of dates, such as what order the day, month and year are in.

In number formatting, not only does the character used to delineate number groupings and the decimal portion differ, but the placement of those characters differ as well.

A user using an application should be able to read and write dates and numbers in the format they are accustomed to, following libraries makes this possible.

i18next (6.8k ⭐) - An i18n-framework written in and for JavaScript. i18next goes beyond just providing the standard i18n features such as (plurals, context, interpolation, format). It provides you with a complete solution to localize your product from web to mobile and desktop.

FormatJS (13.7 ⭐) - A modular collection of JavaScript libraries for internationalization that are focused on formatting numbers, dates, and strings for displaying to people. It includes a set of core libraries that build on the JavaScript Intl built-ins and industry-wide i18n standards, plus a set of integrations for common template and component libraries.

FBT (3.8k ⭐) - A framework for internationalizing user interfaces in JavaScript, developed by Facebook, designed to be not only powerful and flexible, but also simple and intuitive.

Polyglot.js (3.6k ⭐) - A tiny I18n helper library written in JavaScript, made to work both in the browser and Node.js. It provides a simple solution for interpolation and pluralization, based off of Airbnb’s experience adding I18n functionality to its Backbone.js and Node apps.

Globalize (4.7k ⭐) - A JavaScript library for internationalization and localization that leverages the official Unicode CLDR JSON data, designed to work both in the browser and Node.js, supports both AMD and CommonJS.

LinguiJS (3.7k ⭐) - Lingui is an easy yet powerful internationalization framework for JavaScript.

Common features

JavaScript i18n (internationalization) libraries provide various features and tools to facilitate the localization and internationalization of web applications. While specific libraries may have unique functionalities, here are some common features found in JavaScript i18n libraries:

Message translation: JavaScript i18n libraries typically provide translation capabilities, allowing developers to define translations for different languages. These libraries often include functions or APIs to handle message translation and substitution, enabling developers to display localized content based on the user’s language preferences.

Pluralization and grammatical rules: Internationalization involves more than just translating words; it also requires handling plural forms and grammatical variations based on different languages. Many i18n libraries offer support for pluralization rules, allowing developers to define different translations based on count or other criteria.

Locale management: JavaScript i18n libraries often provide mechanisms for managing locales, allowing developers to set the current locale or detect the user’s preferred language. They may also include utilities for language negotiation and language fallbacks, enabling the application to adapt to the user’s language settings.

Date and time formatting: Localization frequently involves formatting dates, times, and other temporal information according to different language conventions. i18n libraries often include functions or utilities for formatting and parsing dates and times based on the user’s locale.

Number formatting: Handling number formatting based on locale-specific conventions is another important aspect of internationalization. JavaScript i18n libraries may provide functions or utilities for formatting numbers, currencies, decimals, and percentages according to the user’s locale.

Text direction and layout support: Certain languages, such as Arabic or Hebrew, are written right-to-left (RTL), requiring special handling for text direction and layout. Some i18n libraries offer support for RTL languages, including features for automatic text direction detection and layout adjustments.

Pluggable architecture and customization: Many JavaScript i18n libraries are designed with a pluggable architecture, allowing developers to extend or customize their functionalities. This enables developers to adapt the library to specific requirements or integrate with existing localization tools and workflows.

Message extraction and management: Some i18n libraries provide tools or utilities to extract translatable messages from the source code and manage translation files. These tools may help streamline the translation process by identifying new or updated messages and providing a workflow for translators.

It’s important to note that the specific features and capabilities of JavaScript i18n libraries may vary, and it’s recommended to refer to the documentation of each library for a detailed understanding of their offerings.