---
title: ".js file — what it is and how to open it"
description: "A .js file is a JavaScript Source. The programming language of the web, in a plain-text file. How to open one on Windows, macOS and Linux, and what to convert it to."
url: https://atoneplace.net/file/js/
site: "At One Place"
---

# .js files

**.js file: JavaScript Source**

The programming language of the web, in a plain-text file.

## What opens a .js file

- **Windows:** Visual Studio Code, Notepad++, Notepad (built in)
- **macOS:** Visual Studio Code, TextEdit (built in), BBEdit
- **Linux:** Visual Studio Code, Text Editor (built in), Vim
- **In a browser:** CodeSandbox, JSFiddle

## What a .js file is

JavaScript runs in every browser and, through Node.js, on servers and desktops too; the language is standardised as ECMAScript. A .js file is readable text, so any editor opens it — but a downloaded .js can also be a script Windows will execute if you double-click it, which is a long-standing malware route. Open unknown ones in an editor rather than launching them.

## Converting it

A .js file is commonly converted to .ts, .mjs or .txt. It is a plain text format, so any text editor can open and edit it directly.

## Details

- **Extension:** .js
- **Full name:** JavaScript Source
- **Category:** Code and scripts
- **MIME type:** text/javascript
- **Created by:** Brendan Eich / Ecma International
- **Format:** Plain text

## Common questions

### How do I open a .js file?

On Windows use Visual Studio Code; on macOS use Visual Studio Code; on Linux use Visual Studio Code. The programming language of the web, in a plain-text file.

### What is a .js file?

JavaScript Source. JavaScript runs in every browser and, through Node.js, on servers and desktops too; the language is standardised as ECMAScript. A .js file is readable text, so any editor opens it — but a downloaded .js can also be a script Windows will execute if you double-click it, which is a long-standing malware route.

### Can I convert a .js file?

Yes. It is usually converted to .ts, .mjs or .txt, either by exporting from one of the programs listed above or with a format converter.

## Related pages

- [.html — HyperText Markup Language](https://atoneplace.net/file/html/)
- [.css — Cascading Style Sheet](https://atoneplace.net/file/css/)
- [.py — Python Source](https://atoneplace.net/file/py/)
- [.java — Java Source](https://atoneplace.net/file/java/)
- [.tsx — TypeScript Source (JSX)](https://atoneplace.net/file/tsx/)
- [.cpp — C++ Source](https://atoneplace.net/file/cpp/)
- [.php — PHP Source](https://atoneplace.net/file/php/)
- [.c — C Source](https://atoneplace.net/file/c/)
- [.cs — C# Source](https://atoneplace.net/file/cs/)
- [.go — Go Source](https://atoneplace.net/file/go/)
- [.rs — Rust Source](https://atoneplace.net/file/rs/)
- [.rb — Ruby Source](https://atoneplace.net/file/rb/)

## Sources

- Media Types Registry — IANA (https://www.iana.org/assignments/media-types/)
- Official vendor product documentation — At One Place (/about/)