Overview

text/javascript is the media type for JavaScript source executed by browsers. Once slated for deprecation, it was revived by the current WHATWG HTML standard as the recommended type for serving scripts, and is today the de facto type for JS loaded via <script>.

Details

RFC 4329 once treated application/javascript as canonical and marked text/javascript 'obsolete,' but because the real web overwhelmingly used text/javascript, WHATWG re-designated it as the official recommended type for interoperability. Browsers execute text/javascript and application/javascript identically, and `charset=utf-8` decodes non-ASCII strings and identifiers in the source correctly.

It matters that your static server or CDN maps .js to text/javascript. In particular, ES modules (<script type="module">, .mjs) require an exact JavaScript MIME type, and a wrong type makes the browser refuse execution under enforced nosniff.

Syntax

e.g. Content-Type: text/javascript; charset=utf-8

File extensions

Notes

• text/javascript and application/javascript are equivalent for execution; the current standard recommends text/javascript for interoperability.
• ES modules are rejected unless the MIME is exact — register .js and .mjs in the server's MIME map.
• Serving user content with this type means immediate code execution (XSS) and is strictly forbidden.

Related types

Related headers