RFC 2616 - Hypertext Transfer Protocol -- HTTP/1.1

RFC 2616 - Hypertext Transfer Protocol -- HTTP/1.1 Light Dark Auto RFC 2616 Draft Standard Title Hypertext Transfer Protocol -- HTTP/1.1 Document Document type RFC - Draft Standard June 1999 View errata Report errata Obsoleted by RFC 7230, RFC 7231, RFC 7232, RFC 7233, RFC 7234, RFC 7235 Updated by RFC 5785, RFC 6266, RFC 6585, RFC 2817 Obsoletes RFC 2068 Was draft-ietf-http-v11-spec-rev (http WG) Select version 06 RFC 2616 Compare versions RFC 2616 draft-ietf-http-v11-spec-rev-06 draft-ietf-http-v11-spec-rev-05 draft-ietf-http-v11-spec-rev-04 draft-ietf-http-v11-spec-rev-03 draft-ietf-http-v11-spec-rev-02 draft-ietf-http-v11-spec-rev-01 draft-ietf-http-v11-spec-rev-00 RFC 2616 draft-ietf-http-v11-spec-rev-06 draft-ietf-http-v11-spec-rev-05 draft-ietf-http-v11-spec-rev-04 draft-ietf-http-v11-spec-rev-03 draft-ietf-http-v11-spec-rev-02 draft-ietf-http-v11-spec-rev-01 draft-ietf-http-v11-spec-rev-00 Side-by-side Inline Authors R. Fielding , J. Gettys , J. Mogul , H. Frystyk , L. Masinter , P. Leach , T. Berners-Lee Email authors RFC stream Other formats txt html pdf w/errata bibtex Additional resources Mailing list discussion Report a bug Network Working Group R. Fielding Request for Comments: 2616 UC Irvine Obsoletes: 2068 J. Gettys Category: Standards Track Compaq/W3C J. Mogul Compaq H. Frystyk W3C/MIT L. Masinter Xerox P. Leach Microsoft T. Berners-Lee W3C/MIT June 1999 Hypertext Transfer Protocol -- HTTP/1.1 Status of this Memo This document specifies an Internet standards track protocol for the Internet community, and requests discussion and suggestions for improvements. Please refer to the current edition of the "Internet Official Protocol Standards" (STD 1) for the standardization state and status of this protocol. Distribution of this memo is unlimited. Copyright Notice Copyright (C) The Internet Society (1999). All Rights Reserved. Abstract The Hypertext Transfer Protocol (HTTP) is an application-level protocol for distributed, collaborative, hypermedia information systems. It is a generic, stateless, protocol which can be used for many tasks beyond its use for hypertext, such as name servers and distributed object management systems, through extension of its request methods, error codes and headers [47]. A feature of HTTP is the typing and negotiation of data representation, allowing systems to be built independently of the data being transferred. HTTP has been in use by the World-Wide Web global information initiative since 1990. This specification defines the protocol referred to as "HTTP/1.1", and is an update to RFC 2068 [33]. Fielding, et al. Standards Track [Page 1] RFC 2616 HTTP/1.1 June 1999 Table of Contents 1 Introduction ...................................................7 1.1 Purpose......................................................7 1.2 Requirements .................................................8 1.3 Terminology ..................................................8 1.4 Overall Operation ...........................................12 2 Notational Conventions and Generic Grammar ....................14 2.1 Augmented BNF ...............................................14 2.2 Basic Rules .................................................15 3 Protocol Parameters ...........................................17 3.1 HTTP Version ................................................17 3.2 Uniform Resource Identifiers ................................18 3.2.1 General Syntax ...........................................19 3.2.2 http URL .................................................19 3.2.3 URI Comparison ...........................................20 3.3 Date/Time Formats ...........................................20 3.3.1 Full Date ................................................20 3.3.2 Delta Seconds ............................................21 3.4 Character Sets ..............................................21 3.4.1 Missing Charset ..........................................22 3.5 Content Codings .............................................23 3.6 Transfer Codings ............................................24 3.6.1 Chunked Transfer Coding ..................................25 3.7 Media Types .................................................26 3.7.1 Canonicalization and Text Defaults .......................27 3.7.2 Multipart Types ..........................................27 3.8 Product Tokens ..............................................28 3.9 Quality Values ..............................................29 3.10 Language Tags ...............................................29 3.11 Entity Tags .................................................30 3.12 Range Units .................................................30 4 HTTP Message ..................................................31 4.1 Message Types ...............................................31 4.2 Message Headers .............................................31 4.3 Message Body ................................................32 4.4 Message Length ..............................................33 4.5 General Header Fields .......................................34 5 Request .......................................................35 5.1 Request-Line ................................................35 5.1.1 Method ...................................................36 5.1.2 Request-URI ..............................................36 5.2 The Resource Identified by a Request ........................38 5.3 Request Header Fields .......................................38 6 Response ......................................................39 6.1 Status-Line .................................................39 6.1.1 Status Code and Reason Phrase ............................39 6.2 Response Header Fields ......................................41 Fielding, et al. Standards Track [Page 2] RFC 2616 HTTP/1.1 June 1999 7 Entity ........................................................42 7.1 Entity Header Fields ........................................42 7.2 Entity Body .................................................43 7.2.1 Type .....................................................43 7.2.2 Entity Length ............................................43 8 Connections ...................................................44 8.1 Persistent Connections ......................................44 8.1.1 Purpose ..................................................44 8.1.2 Overall Operation ........................................45 8.1.3 Proxy Servers ............................................46 8.1.4 Practical Considerations .................................46 8.2 Message Transmission Requirements ...........................47 8.2.1 Persistent Connections and Flow Control ..................47 8.2.2 Monitoring Connections for Error Status Messages .........48 8.2.3 Use of the 100 (Continue) Status .........................48 8.2.4 Client Behavior if Server Prematurely Closes Connection ..50 9 Method Definitions ............................................51 9.1 Safe and Idempotent Methods .................................51 9.1.1 Safe Methods .............................................51 9.1.2 Idempotent Methods .......................................51 9.2 OPTIONS .....................................................52 9.3 GET .........................................................53 9.4 HEAD ........................................................54 9.5 POST ........................................................54 9.6 PUT .........................................................55 9.7 DELETE ......................................................56 9.8 TRACE .......................................................56 9.9 CONNECT .....................................................57 10 Status Code Definitions ......................................57 10.1 Informational 1xx ...........................................57 10.1.1 100 Continue .............................................58 10.1.2 101 Switching Protocols ..................................58 10.2 Successful 2xx ..............................................58 10.2.1 200 OK ...................................................58 10.2.2 201 Created ..............................................59 10.2.3 202 Accepted .............................................59 10.2.4 203 Non-Authoritative Information ........................59 10.2.5 204 No Content ...........................................60 10.2.6 205 Reset Content ........................................60 10.2.7 206 Partial Content ......................................60 10.3 Redirection 3xx .............................................61 10.3.1 300 Multiple Choices .....................................61 10.3.2 301 Moved Permanently ....................................62 10.3.3 302 Found ................................................62 10.3.4 303 See Other ............................................63 10.3.5 304 Not Modified .........................................63 10.3.6 305 Use Proxy ............................................64 10.3.7 306 (Unused) .............................................64 Fielding, et al. Standards Track [Page 3] RFC 2616 HTTP/1.1 June 1999 10.3.8 307 Temporary Redirect ...................................65 10.4 Client Error 4xx ............................................65 10.4.1 400 Bad Request .........................................65 10.4.2 401 Unauthorized ........................................66 10.4.3 402 Payment Required ....................................66 10.4.4 403 Forbidden ...........................................66 10.4.5 404 Not Found ...........................................66 10.4.6 405 Method Not Allowed ..................................66 10.4.7 406 Not Acceptable ......................................67 10.4.8 407 Proxy Authentication Required .......................67 10.4.9 408 Request Timeout .....................................67 10.4.10 409 Conflict ............................................67 10.4.11 410 Gone ................................................68 10.4.12 411 Length Required .....................................68 10.4.13 412 Precondition Failed .................................68 10.4.14 413 Request Entity Too Large ............................69 10.4.15 414 Request-URI Too Long ................................69 10.4.16 415 Unsupported Media Type ..............................69 10.4.17 416 Requested Range Not Satisfiable .....................69 10.4.18 417 Expectation Failed ..................................70 10.5 Server Error 5xx ............................................70 10.5.1 500 Internal Server Error ................................70 10.5.2 501 Not Implemented ......................................70 10.5.3 502 Bad Gateway ..........................................70 10.5.4 503 Service Unavailable ..................................70 10.5.5 504 Gateway Timeout ......................................71 10.5.6 505 HTTP Version Not Supported ...........................71 11 Access Authentication ........................................71 12 Content Negotiation ..........................................71 12.1 Server-driven Negotiation ...................................72 12.2 Agent-driven Negotiation ....................................73 12.3 Transparent Negotiation .....................................74 13 Caching in HTTP ..............................................74 13.1.1 Cache Correctness ........................................75 13.1.2 Warnings .................................................76 13.1.3 Cache-control Mechanisms .................................77 13.1.4 Explicit User Agent Warnings .............................78 13.1.5 Exceptions to the Rules and Warnings .....................78 13.1.6 Client-controlled Behavior ...............................79 13.2 Expiration Model ............................................79 13.2.1 Server-Specified Expiration ..............................79 13.2.2 Heuristic Expiration .…