Intl in JavaScript

Locale-aware numbers, dates and relative times, built in.

const number = new Intl.NumberFormat("en-GB", {
  style: "unit",
  unit: "minute",
  maximumFractionDigits: 1,
});
console.log(number.format(104.55));

const money = new Intl.NumberFormat("en-US", {
  style: "currency",
  currency: "USD",
});
console.log(money.format(1234.5));

const when = new Intl.DateTimeFormat("en-GB", {
  dateStyle: "medium",
  timeStyle: "short",
  timeZone: "UTC",
});
console.log(when.format(new Date("2026-07-30T09:05:00Z")));

const ago = new Intl.RelativeTimeFormat("en", { numeric: "auto" });
console.log(ago.format(-3, "day"), ago.format(1, "week"));

console.log(new Intl.ListFormat("en").format(["go", "rust", "sql"]));

How it works

1. A formatter is reusable and worth keeping.
2. RelativeTimeFormat writes phrases like three days ago.
3. ListFormat joins with the right conjunction.

Keywords and builtins used here

• Date
• Intl
• const

The run, in numbers

Lines

24

Characters to type

637

Tokens

179

Three-star pace

105 tpm

At the three-star pace of 105 tokens a minute, this run takes about 102 seconds.

Type this snippet

Step 2 of 2 in URLs & formatting, step 12 of 13 in The browser.

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