.JS File Extension

File Type 1

JavaScript File

Developer N/A
4.0  |  297 Votes
Category Web Files
Format Text

What is a JS file?

A JS file is a plain text file that contains JavaScript code. It is used to execute JavaScript instructions in a webpage. JS files may include functions that open and close windows, validate form fields, enable rollover images, or create dropdown menus.

More Information
Screenshot of a .js file in Microsoft Visual Studio Code
JS file open in Microsoft Visual Studio Code

Web developers use JavaScript to add dynamic and interactive elements to webpages. One of the ways developers can add JavaScript functions to a webpage is by importing them using a JS file.

Developers usually import JS files in the <head> or <body> sections of a webpage's HTML, as shown below:

<head> <script type="text/javascript" src="FileInfo.comExample.js"></script> </head>

JS files often contain standard or site-wide functions that a developer wants to include on each of a site's webpages. Storing the functions in a single, importable JS file makes them easier to maintain and troubleshoot.

How to open a JS file

You can open and edit a JS file in any text or source code editor. Source code editors, such as Microsoft Visual Studio Code and GitHub Atom contain helpful syntax-highlighting and code-editing tools that make reading and editing JS files easier.

Open and view .JS files with File Viewer Plus.Free Download

Programs that open JS files

Updated April 22, 2022
File Type 2

JScript Executable Script

Developer N/A
3.7  |  87 Votes
Category Executable Files
Format N/A

Executable script written in JScript, Microsoft's version of JavaScript

Programs that open JS files

Windows-based script host (Wscript.exe)
Updated 2006

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