Select Page

How to Internationalize Numbers with JavaScript

David Walsh
Published: November 21, 2022

Presenting numbers in a readable format takes many forms, from visual charts to simply adding punctuation. Those punctuation, however, are different based on internationalization. Some countries use , for decimal, while others use .. Worried about having to code for all this madness? Don’t — JavaScript provides a method do the hard work for you!

The Number primitive has a toLocaleString method to do the basic formatting for you:

const price = 16601.91;
// Basic decimal format, no providing locale
// Uses locale provided by browser since none defined
price.toLocaleString(); // "16,601.91"
// Provide a specific locale
price.toLocaleString('de-DE'); // "16.601,91"
// Formatting currency is possible
price.toLocaleString('de-DE', { 
  style: 'currency', 
  currency: 'EUR' 
}); // "16.601,91 €"
// You can also use Intl.NumberFormat for formatting
new Intl.NumberFormat('en-US', {
  style: 'currency',
  currency: 'GBP'
}).format(price); // £16,601.91

It’s a major relief that JavaScript provides us these type of helpers so that we don’t need to rely on bloated third-party libraries. No excuses — the tool is there!

  • Conquering Impostor Syndrome

    Two years ago I documented my struggles with Imposter Syndrome and the response was immense.  I received messages of support and commiseration from new web developers, veteran engineers, and even persons of all experience levels in other professions.  I’ve even caught myself reading the post…

  • Responsive Images: The Ultimate Guide

    Chances are that any Web designers using our Ghostlab browser testing app, which allows seamless testing across all devices simultaneously, will have worked with responsive design in some shape or form. And as today’s websites and devices become ever more varied, a plethora of responsive images…



Source: davidwalsh.name