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headers

The full list of HTTP headers is shared with MIME headers and is maintained by the IANA at Message Headers

Headers by Function

Informational

Resource Metadata

Transfer Control

Entity Body and Partial Content

Caching

Conditional Requests

Authentication and Access Control

Content-Type Negotiation

Crafting New Headers

See RFC7231 Section 8.3.1.

If the response is identifying another resource, use the Link header with a URI as the relation name, e.g.:

Link: <http://example.com/AcmeMetals>;rel="http://example.com/coin-minted-by"

Table of Headers

HeaderDescriptionReference
A-IMRFC4229
AcceptRFC7231, Section 5.3.2
Accept-AdditionsUsed in Hyper Text Coffee Pot Control Protocol (HTCPCP/1.0)RFC2324
Accept-CharsetRFC7231, Section 5.3.3
Accept-DatetimeRFC7089
Accept-EncodingRFC7231, Section 5.3.4
Accept-FeaturesExperimentalRFC2995
Accept-LanguageLocales that a user agent prefersRFC7231, Section 5.3.5
Accept-PatchSpecifies media types that are acceptable for PATCH requestsRFC5789
Accept-RangesServer indication of which range units it understands (e.g. byte)RFC7233, Section 2.3
AgeEstimate of how stale the resource is, in seconds, used by cachesRFC7234, Section 5.1
AllowIndicate which methods can be used on the resourceRFC7231, Section 7.4.1
AlternatesExperimentalRFC2295
Apply-To-Redirect-RefRFC4437
Authentication-InfoControl data and information about the authentication sessionRFC4229
AuthorizationCredentials for accessing a resource on the serverRFC7235, Section 4.2
Cache-ControlInformation for how and when to cache the resourceRFC7234, Section 5.2
CloseNot actually a valid header. Reserved to prevent conflicts with Connection: closeRFC7230, Section 8.1
ConnectionRFC7230, Section 6.1
Content-BaseProvides a base URI for the document (largely unsupported and obsolete)RFC2068RFC2616
Content-DispositionConveys additional information about how to process the response payloadRFC6266
Content-EncodingSee also Transfer-EncodingRFC7231, Section 3.1.2.2
Content-IDObsoleteRFC4229 DRP
Content-LanguageThe locale/language of the entity-bodyRFC7231, Section 3.1.3.2
Content-LengthThe octet (byte) length of the attached entity-bodyRFC7230, Section 3.3.2
Content-LocationThe URI of the attached entity-bodyRFC7231, Section 3.1.4.2
Content-MD5ObsoleteRFC4229
Content-RangeIdentifies the enclose entity-body is a subset of the requested resourceRFC7233, Section 4.2
Content-Script-TypeHTML 4.01 Section 18.2.2
Content-Style-TypeHTML 4.01 Section 14.2.1
Content-TypeThe media type of the attached entity-bodyRFC7231, Section 3.1.1.5
Content-VersionObsoleteRFC4229
CookieDeclares a stored cookie value to the serverRFC6265
Cookie2Declares a stored cookie value to the server; ObsoleteRFC2965RFC6265
DASLRFC5323
DAVUsed in WebDAVRFC4918
DateThe date and time at which the message was originatedRFC7231, Section 7.1.1.2
Default-StyleHTML 4.01 Section 14.3.2
Delta-BaseThe entity tag of the base instance against which the delta appliesRFC4229
DepthUsed in WebDAVRFC4918
Derived-FromRFC4229
DestinationUsed in WebDAVRFC4918
Differential-IDRFC4229
DigestIndicates a hash/digest for the full resourceRFC4229
ETagDifferentiates between multiple versions/representations of the same resourceRFC7232, Section 2.3
ExpectRequire that downstream nodes support specified functionalityRFC7231, Section 5.1.1
ExpiresControls cachingRFC7234, Section 5.3
ExtRFC4229
ForwardedShows where the message originated from, further upstreamRFC7239
FromContact information for the user making the request, especially for Web spidersRFC7231, Section 5.5.1
HostHostname component of the request-URI (Required)RFC7230, Section 5.4
IMInstance ManipulationRFC4229 RFC 3229
IfUsed in WebDAVRFC4918
If-MatchConditional request headerRFC7232, Section 3.1
If-Modified-SinceConditional request headerRFC7232, Section 3.3
If-None-MatchConditional request headerRFC7232, Section 3.2
If-RangeConditional request headerRFC7233, Section 3.2
If-Schedule-Tag-MatchPart of Scheduling Extensions to CalDAVRFC6638
If-Unmodified-SinceConditional request headerRFC7232, Section 3.4
Keep-AliveRFC4229
LabelUsed in WebDAVRFC4229
Last-ModifiedRFC7232, Section 2.2
LinkDeclares a link relationship to another resourceRFC5988
LocationPoints to another resource, typically for redirection purposesRFC7231, Section 7.1.2
Lock-TokenUsed in WebDAVRFC4918
ManExperimentalRFC4229
Max-ForwardsLimit the number of forwards, similar to a TTLRFC7231, Section 5.1.2
Memento-DatetimeRFC7089
MeterRFC4229 RFC2227
MIME-VersionThe HTTP Message is also MIME compatible (obsolete)RFC7231, Appendix A.1
NegotiateRFC4229 RFC2295
OptRFC4229
Ordering-TypeRFC4229
OriginRFC6454
OverwriteUsed in WebDAVRFC4918
P3PRFC4229
PEPRFC4229
PICS-LabelRFC4229
Pep-InfoRFC4229
PositionRFC4229
Pragma(Deprecated HTTP/1.0 header)RFC7234, Section 5.4
PreferIndicate a preference for how the server should respond to a queryRFC7240
Preference-AppliedRFC7240
ProfileObjectRFC4229
Proxy-AuthenticateUse of proxy requires authenticationRFC7235, Section 4.3
Proxy-Authentication-InfoRFC4229
Proxy-AuthorizationSend credentials to a proxyRFC7235, Section 4.4
Proxy-FeaturesRFC4229
Proxy-InstructionRFC4229
PublicRFC4229
RangeRequest a subset of the resourceRFC7233, Section 3.1
Redirect-RefRFC4437
Referer(Sic) Page that was linked fromRFC7231, Section 5.5.2
Retry-AfterRFC7231, Section 7.1.3
SafeRFC4229
Schedule-ReplyPart of Scheduling Extensions to CalDAVRFC6638
Schedule-TagPart of Scheduling Extensions to CalDAVRFC6638
Sec-WebSocket-AcceptUsed for negotiating a WebSocket connectionRFC6455
Sec-WebSocket-ExtensionsUsed for negotiating a WebSocket connectionRFC6455
Sec-WebSocket-KeyUsed for negotiating a WebSocket connectionRFC6455
Sec-WebSocket-ProtocolUsed for negotiating a WebSocket connectionRFC6455
Sec-WebSocket-VersionUsed for negotiating a WebSocket connectionRFC6455
Security-SchemeUsed to indicate S-HTTP support (not to be confused with HTTPS)RFC4229
ServerIndicates the server’s software and versionRFC7231, Section 7.4.2
Set-CookieRequest to store a cookie on the user-agentRFC6265
Set-Cookie2Request to store a cookie on the user-agent; ObsoleteRFC2965RFC6265
SlugSpecifies a “slug” string to be used in the generation of URLs of new resources. Used by the Atom Publishing Protocol.RFC5023
SoapActionRFC4229
Status-URIUsed by WebDAVRFC4229
Strict-Transport-SecurityHSTS, asks that future requests must only go over TLSRFC6797
Surrogate-CapabilityRFC4229
Surrogate-ControlRFC4229
TCNRFC4229
TERFC7230, Section 4.3
TimeoutUsed in WebDAVRFC4918
TrailerRFC7230, Section 4.4
Transfer-EncodingSpecifies how the payload has been compressed. See also Content-EncodingRFC7230, Section 3.3.1
URIRFC4229
UpgradeRFC7230, Section 6.7
User-AgentIndicates the user agent’s software and versionRFC7231, Section 5.5.3
Variant-VaryRFC4229
VaryThe server’s response was chosen based on the specified headersRFC7231, Section 7.1.4
ViaRFC7230, Section 5.7.1
WWW-AuthenticateRFC7235, Section 4.1
Want-DigestRFC4229
WarningRFC7234, Section 5.5
X-Frame-OptionsOlder variation on Frame-Options headerRFC7034 CSP