List of HTTP header fields
Standard request fields

List of HTTP header fields

Section Title: Standard request fields
Table Section Text: None

Header field name	Description	Example	Status

A-IM	Acceptable instance-manipulations for the request.	A-IM: feed	Permanent

Accept	Media type(s) that is/are acceptable for the response. See Content negotiation.	Accept: text/html	Permanent

Accept-Charset	Character sets that are acceptable.	Accept-Charset: utf-8	Permanent

Accept-Encoding	List of acceptable encodings. See HTTP compression.	Accept-Encoding: gzip, deflate	Permanent

Accept-Language	List of acceptable human languages for response. See Content negotiation.	Accept-Language: en-US	Permanent

Accept-Datetime	Acceptable version in time.	Accept-Datetime: Thu, 31 May 2007 20:35:00 GMT	Provisional

Access-Control-Request-Method, Access-Control-Request-Headers	Initiates a request for cross-origin resource sharing with Origin (below).	Access-Control-Request-Method: GET	Permanent: standard

Authorization	Authentication credentials for HTTP authentication.	Authorization: Basic QWxhZGRpbjpvcGVuIHNlc2FtZQ==	Permanent

Cache-Control	Used to specify directives that must be obeyed by all caching mechanisms along the request-response chain.	Cache-Control: no-cache	Permanent

Connection	Control options for the current connection and list of hop-by-hop request fields. Must not be used with HTTP/2.	Connection: keep-alive Connection: Upgrade	Permanent

Content-Length	The length of the request body in octets (8-bit bytes).	Content-Length: 348	Permanent

Content-MD5	A Base64-encoded binary MD5 sum of the content of the request body.	Content-MD5: Q2hlY2sgSW50ZWdyaXR5IQ==	Obsolete

Content-Type	The Media type of the body of the request (used with POST and PUT requests).	Content-Type: application/x-www-form-urlencoded	Permanent

Cookie	An HTTP cookie previously sent by the server with Set-Cookie (below).	Cookie: $Version=1; Skin=new;	Permanent: standard

Date	The date and time at which the message was originated (in "HTTP-date" format as defined by RFC 7231 Date/Time Formats).	Date: Tue, 15 Nov 1994 08:12:31 GMT	Permanent

Expect	Indicates that particular server behaviors are required by the client.	Expect: 100-continue	Permanent

Forwarded	Disclose original information of a client connecting to a web server through an HTTP proxy.	Forwarded: for=192.0.2.60;proto=http;by=203.0.113.43 Forwarded: for=192.0.2.43, for=198.51.100.17	Permanent

From	The email address of the user making the request.	From: user@example.com	Permanent

Host	The domain name of the server (for virtual hosting), and the TCP port number on which the server is listening. The port number may be omitted if the port is the standard port for the service requested.	Host: en.wikipedia.org:8080 Host: en.wikipedia.org	Permanent

HTTP2-Settings	A request that upgrades from HTTP/1.1 to HTTP/2 MUST include exactly one HTTP2-Setting header field. The HTTP2-Settings header field is a connection-specific header field that includes parameters that govern the HTTP/2 connection, provided in anticipation of the server accepting the request to upgrade.	HTTP2-Settings: token64	Permanent: standard

If-Match	Only perform the action if the client supplied entity matches the same entity on the server. This is mainly for methods like PUT to only update a resource if it has not been modified since the user last updated it.	If-Match: "737060cd8c284d8af7ad3082f209582d"	Permanent

If-Modified-Since	Allows a 304 Not Modified to be returned if content is unchanged.	If-Modified-Since: Sat, 29 Oct 1994 19:43:31 GMT	Permanent

If-None-Match	Allows a 304 Not Modified to be returned if content is unchanged, see HTTP ETag.	If-None-Match: "737060cd8c284d8af7ad3082f209582d"	Permanent

If-Range	If the entity is unchanged, send me the part(s) that I am missing; otherwise, send me the entire new entity.	If-Range: "737060cd8c284d8af7ad3082f209582d"	Permanent

If-Unmodified-Since	Only send the response if the entity has not been modified since a specific time.	If-Unmodified-Since: Sat, 29 Oct 1994 19:43:31 GMT	Permanent

Max-Forwards	Limit the number of times the message can be forwarded through proxies or gateways.	Max-Forwards: 10	Permanent

Origin	Initiates a request for cross-origin resource sharing (asks server for Access-Control-* response fields).	Origin: http://www.example-social-network.com	Permanent: standard

Pragma	Implementation-specific fields that may have various effects anywhere along the request-response chain.	Pragma: no-cache	Permanent

Proxy-Authorization	Authorization credentials for connecting to a proxy.	Proxy-Authorization: Basic QWxhZGRpbjpvcGVuIHNlc2FtZQ==	Permanent

Range	Request only part of an entity. Bytes are numbered from 0. See Byte serving.	Range: bytes=500-999	Permanent

Referer [sic]	This is the address of the previous web page from which a link to the currently requested page was followed. (The word “referrer” has been misspelled in the RFC as well as in most implementations to the point that it has become standard usage and is considered correct terminology)	Referer: http://en.wikipedia.org/wiki/Main_Page	Permanent

TE	The transfer encodings the user agent is willing to accept: the same values as for the response header field Transfer-Encoding can be used, plus the "trailers" value (related to the "chunked" transfer method) to notify the server it expects to receive additional fields in the trailer after the last, zero-sized, chunk.	TE: trailers, deflate	Permanent

User-Agent	The user agent string of the user agent.	User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:12.0) Gecko/20100101 Firefox/12.0	Permanent

Upgrade	Ask the server to upgrade to another protocol. Must not be used in HTTP/2.	Upgrade: h2c, HTTPS/1.3, IRC/6.9, RTA/x11, websocket	Permanent

Via	Informs the server of proxies through which the request was sent.	Via: 1.0 fred, 1.1 example.com (Apache/1.1)	Permanent

Warning	A general warning about possible problems with the entity body.	Warning: 199 Miscellaneous warning	Permanent

Sentence(s)

The Range header is used to request a specific part of a file.

final_sentence: The Range header is used to request a specific part of a file.