Browse all MIME types

application/javascript

JavaScript responses tell browsers and runtimes to execute source code, so correct MIME headers matter for module loading and CSP-safe delivery.

application
Compressible in transit

Content-Type header

Content-Type: application/javascript
Common extensions
.js

How teams usually encounter it

This page maps the media type to the file extensions and delivery behaviors developers usually care about: browser parsing, upload validation, cache correctness, and asset handling.

Compression signal

application/javascript often benefits from gzip or Brotli in HTTP delivery because the payload is text-like or structurally repetitive.

Server config snippets

Use these when a server is missing the right extension-to-MIME mapping or you want the expected header to survive a proxy, CDN, or custom asset bucket setup.

Nginx
types {
  application/javascript js;
}
Apache
AddType application/javascript .js

Signature note

This MIME type does not include a magic-byte sample here because the signature is either format-dependent or not reliable enough to present as a debugging shortcut.

Operational shortcut

If a browser downloads this asset instead of rendering it correctly, check the response header first, then verify the extension mapping on your origin and edge cache. .js is the fastest sanity check for teammates reviewing the file outside the app.

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