Accept-Encoding

E200845

Accept-Encoding is an HTTP request header that tells the server which content-encoding algorithms (like gzip or deflate) the client can handle so the server can choose an appropriate compression method.

All labels observed (1)

Label Occurrences
Accept-Encoding canonical 1

How this entity was disambiguated

Statements (46)

Predicate Object
instanceOf HTTP request header field
allows content negotiation for content-encoding
canBeOverriddenBy intermediary proxies
canInclude *
br
compress
deflate
gzip
identity
contrastsWith Accept header, which negotiates media types
Accept-Charset header, which negotiates character sets
Accept-Language header, which negotiates natural languages
defaultSemantics if header is absent, server may assume client accepts identity encoding only
definedIn RFC 2616
RFC 7231
exampleUse clients advertise support for gzip to receive compressed responses
fieldType request header
fieldValueType list of codings with optional quality values
hasPurpose indicate acceptable content-encoding algorithms to the server
headerCategory representation metadata
headerName Accept-Encoding
improves bandwidth efficiency
page load performance
influences server choice of response content-encoding
introducedIn HTTP/1.1
isCaseInsensitive true
mustNotContain message body
partOf HTTP/1.1 specification
processingRule if no acceptable encoding is available, server may respond with 406 Not Acceptable
server selects one encoding from the acceptable set or returns unencoded content
relatedSecurityConsideration compression side-channel attacks such as BREACH
relatesTo Content-Encoding
Transfer-Encoding
semantics higher q value indicates higher preference for an encoding
identity encoding is always acceptable unless explicitly refused with q=0
q=0 means encoding is not acceptable
status standard header
supportsParameter q (quality value)
wildcard * encoding
syntaxExample Accept-Encoding: gzip, deflate
Accept-Encoding: gzip;q=1.0, br;q=0.8, *;q=0.1
usedBy HTTP clients
HTTP libraries
web browsers
usedFor HTTP response compression
usedIn HTTP requests

How these facts were elicited

Referenced by (1)

Full triples — surface form annotated when it differs from this entity's canonical label.

RFC 7231 definesHeaderField Accept-Encoding