Media types that are acceptable for the response

Accept: text/html, application/xml,...

List of acceptable encodings (HTTP compression types)

Accept-Encoding: gzip, deflate, br

An HTTP cookie previously sent by the server with Set-Cookie (below)

Cookie: _ga=GA1.2.588481944.1592916481; _fbp=fb.1.1592916481604.1420873611; ...

The user agent string of the user agent (browser identifier string)

User-Agent: Mozilla/5.0 (Linux...

Authentication credentials for HTTP authentication

Authorization: Basic QWxhZGRpbjpvcGVuIHNlc2FtZQ==

The email address of the user making the request

From: user@example.com

The length of the request body in octets (8-bit bytes).

Content-Length: 348

... Note:

browsers that do not support compliant compression method will download uncompressed data