application/gzipapplication/gzip is the media type for a single-stream file compressed with the gzip (DEFLATE-based) algorithm. It is commonly combined with tar as `.tar.gz` to distribute file bundles, and used to store compressed logs and backups.
Two concepts must be kept separate here. (1) When the resource itself is a gzip file → Content-Type: application/gzip. (2) When an arbitrary resource is compressed only for transfer → keep the original Content-Type (e.g. text/html) and add `Content-Encoding: gzip`; the browser decompresses automatically to recover the original. Confusing the two — putting Content-Encoding: gzip on a gzip file — makes the browser decompress once, so the user receives an un-gzipped tar.
Clients advertise support with `Accept-Encoding: gzip, br`, and the server negotiates and responds via `Content-Encoding`. Send `Vary: Accept-Encoding` too, so proxies do not serve a compressed body to a client expecting the uncompressed one.
e.g. Content-Type: application/gzip