Internationalize your web apps
on the client & server

Industry-standard i18n libraries for JavaScript. Built on ICU Message syntax.

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50M+/month

NPM Downloads

14K+

GitHub Stars

150+

Languages

1000+

Companies

Why FormatJS?

Industry-standard internationalization built on web standards

FormatJS Integrations

FormatJS Core Libs

ECMA-402 + Polyfills

Modular Libraries

A modular collection of JavaScript libraries focused on formatting numbers, dates, and strings. Core libraries build on JavaScript Intl built-ins and industry-wide i18n standards.

Framework Integrations

Built-in integrations with React and Vue. Internationalization happens in the template or view layer with easy-to-use components and hooks.

Standards Based

Aligned with ECMAScript, ECMA-402, Unicode CLDR, and ICU Message syntax.

Runs in the browser and Node.js.

FormatJS has been tested in all the major browsers (IE11, Chrome, FF & Safari) on both desktop and mobile devices. For many web apps rendering happens on the server, so we made sure FormatJS works perfectly in Node.js. This allows developers to use FormatJS on both the server and client-side of their apps.