HTTP Request Header request header
Header explain Example
Accept Specify the content types the client can receive Accept: text/plain, text/html
Accept-Charset The character encoding set that the browser can accept. Accept-Charset: iso-8859-5
Accept-Encoding Specifies the compression encoding type of content returned by the web server that the browser can support. Accept-Encoding: compress, gzip
Accept-Language Languages ​​accepted by the browser Accept-Language: en,zh
Accept-Ranges You can request one or more sub-range fields of the web page entity Accept-Ranges: bytes
Authorization Authorization certificate for HTTP authorization Authorization: authorization certificate
Cache-Control Specify the caching mechanism that requests and responses follow Cache-Control: no-cache
Connection Indicates whether a persistent connection is required. (HTTP 1.1 makes persistent connections by default) Connection: close
Cookie When an HTTP request is sent, all cookie values ​​stored under the requested domain name will be sent to the web server. Cookie: $Version=1; Skin=new;
Content-Length Requested content length Content-Length: 348
Content-Type The requested MIME information corresponding to the entity Content-Type: application/x-www-form-urlencoded
Date The date and time the request was sent Date: Tue, 15 Nov 2010 08:12:31 GMT
Expect Request specific server behavior Expect: 100-continue
From Email of the user who made the request From: [email protected]
Host Specify the domain name and port number of the requested server Host: www.jsons.cn
If-Match Valid only if the request content matches the entity If-Match: "Specific value"
If-Modified-Since If the requested part is modified after the specified time, the request is successful. If it is not modified, a 304 code is returned. If-Modified-Since: Sat, 29 Oct 2010 19:43:31 GMT
If-None-Match If the content has not changed, a 304 code is returned. The parameter is the Etag previously sent by the server. Compare it with the Etag responded by the server to determine whether it has changed. If-None-Match: "Specific value"
If-Range If the entity has not changed, the server sends the client the missing parts, otherwise the entire entity is sent. The parameter is also Etag If-Range: "Specific value"
If-Unmodified-Since The request succeeds only if the entity has not been modified after the specified time If-Unmodified-Since: Sat, 29 Oct 2010 19:43:31 GMT
Max-Forwards Limit the time that information travels through proxies and gateways Max-Forwards: 10
Pragma Used to contain implementation-specific instructions Pragma: no-cache
Proxy-Authorization Authorization certificate to connect to the agent Proxy-Authorization: Authorization certificate linked to the proxy
Range Request only part of the entity, specify the range Range: bytes=500-999
Referer The address of the previous web page, followed by the current requested web page, that is, the origin Referer: http://www.jsons.cn
TE The client is willing to accept the transfer encoding and notifies the server to accept the tail plus header information. TE: trailers,deflate;q=0.5
Upgrade Specify a transport protocol for the server to convert (if supported) Upgrade: HTTP/2.0, SHTTP/1.3, IRC/6.9, RTA/x11
User-Agent The content of User-Agent contains information about the user who made the request User-Agent: Mozilla/5.0 (Linux; X11)
Via Notify intermediate gateway or proxy server address, communication protocol Via: 1.0 fred, 1.1 nowhere.com (Apache/1.1)
Warning Warning information about message entities Warn: 199 Miscellaneous warning
HTTP Responses Header response header
Header explain Example
Accept-Ranges Indicates whether the server supports the specified range request and what type of segmented request Accept-Ranges: bytes
Age Estimated time in seconds from origin server to proxy cache formation (non-negative) Age: 12
Allow A valid request behavior for a certain network resource. If it is not allowed, 405 will be returned. Allow: GET, HEAD
Cache-Control Tells all caching mechanisms whether they can be cached and of what type Cache-Control: no-cache
Content-Encoding The returned content compression encoding type supported by the web server. Content-Encoding: gzip
Content-Language response body language Content-Language: en,zh
Content-Length Response body length Content-Length: 348
Content-Location Request an alternative address for the resource Content-Location: /index.htm
Content-MD5 Returns the MD5 check value of the resource Content-MD5: MD5 check value
Content-Range The byte position of this part in the entire return body Content-Range: bytes 21010-47021/47022
Content-Type Returns the MIME type of the content Content-Type: text/html; charset=utf-8
Date The time the original server message was sent Date: Tue, 15 Nov 2010 08:12:31 GMT
ETag The current value of the entity tag of the request variable ETag: "Request variable entity tag current value"
Expires Response expiration date and time Expires: Thu, 01 Dec 2010 16:00:00 GMT
Last-Modified The last modification time of the requested resource Last-Modified: Tue, 15 Nov 2010 12:45:26 GMT
Location Used to redirect the recipient to the location of a non-requested URL to complete the request or identify a new resource. Location: http://www.jsons.cn
Pragma Includes implementation-specific directives, which can be applied to any receiver in the response chain Pragma: no-cache
Proxy-Authenticate It indicates the authentication scheme and parameters that can be applied to the proxy on that URL Proxy-Authenticate: Basic
refresh Applies to redirect or a new resource is created, redirect after 5 seconds (proposed by Netscape, supported by most browsers)
Refresh: 5; url= http://www.jsons.cn
Retry-After If the entity is temporarily unavailable, notify the client to try again after the specified time. Retry-After: 120
Server web server software name Server: Apache/1.3.27 (Unix) (Red-Hat/Linux)
Set-Cookie Set HTTP Cookie Set-Cookie: UserID=JohnDoe; Max-Age=3600; Version=1
Trailer Indicates that the header field exists at the end of the chunked transfer encoding Trailer: Max-Forwards
Transfer-Encoding file transfer encoding Transfer-Encoding:chunked
Vary Tells the downstream proxy whether to use a cached response or request from the origin server Vary: *
Via Tells the proxy where the client response is sent through Via: 1.0 fred, 1.1 nowhere.com (Apache/1.1)
Warning Warn about possible problems with entities Warning: 199 Miscellaneous warning
WWW-Authenticate Indicates the authorization scheme that the client requesting entity should use WWW-Authenticate: Basic

Online HTTP response headers, HTTP request headers

HTTP request headers provide information about requests, responses or other sending entities. HTTP header information includes four parts: general header, request header, response header and entity header.

Each header field consists of a domain name, a colon (:) and a domain value.

Universal header: can be used in both requests and responses, and is associated with the transaction as a whole rather than a specific resource

Request headers: allow the client to pass information about itself and the desired response form

Response header: The server and the response that pass its own information

Entity header: defines the information of the resource being transferred, which can be used for both requests and responses.