# Underscores in numbers

> Learn how JavaScript numeric separators let you add underscores inside numbers like 1_000 for readability, a feature available since ECMAScript 2021.

Author: [Flavio Copes](https://flaviocopes.com/about/) | Published: 2025-01-08 | Topics: [JavaScript](https://flaviocopes.com/tags/js/) | Canonical: https://flaviocopes.com/underscores-in-numbers/

TIL you can add underscores in the middle of any number in [JavaScript](https://flaviocopes.com/javascript/), to improve its readability according to what the number means to you:

```javascript
1_000 //1000
2_3_4 //234 
```

It’s a relatively new feature (since **ECMAScript 2021**), but supported by all major browsers since years.

See [https://v8.dev/features/numeric-separators](https://v8.dev/features/numeric-separators)