JS: Source Code Encoding

By Xah Lee. Date: 2017-02-17. Last updated: 2025-05-25.

What is JavaScript's Charset?

JavaScript source code's charset is Unicode.

What is JavaScript's default encoding for source code?

JavaScript spec does not specify a default encoding for source code file.
It depends on the encoding from HTTP protocol configured by the web server. 〔see HTTP Protocol Tutorial〕

UTF-8 encoding is recommended. You should save JavaScript file in UTF-8 encoding. UTF-8 is the standard encoding for much of web technologies.

Reference

js spec 2016 encoding RGcsC — ECMAScript® 2016 Language Specification#sec-ecmascript-language-source-code

HTML CSS JS, Charset and File Encoding