Tip: Use Ctrl+F for quick search
| Header | Description | Example |
|---|---|---|
| Accept | Specifies the content types that the client can accept | Accept: text/plain, text/html |
| Accept-Charset | Character encodings that the browser can accept | Accept-Charset: iso-8859-5 |
| Accept-Encoding | Specifies the compression encoding types that the browser supports | Accept-Encoding: compress, gzip |
| Accept-Language | Languages that the browser can accept | Accept-Language: en, zh |
| Accept-Ranges | Specifies that the request can ask for one or more sub-ranges of the page | Accept-Ranges: bytes |
| Authorization | HTTP authorization credentials | Authorization: Authorization credentials |
| Cache-Control | Specifies the cache directives that the request and response must adhere to | Cache-Control: no-cache |
| Connection | Indicates whether the connection should be persistent. (HTTP 1.1 defaults to persistent connections) | Connection: close |
| Cookie | Sends all cookie values stored under the request domain to the web server | Cookie: $Version=1; Skin=new; |
| Content-Length | The length of the request content | Content-Length: 348 |
| Content-Type | The MIME type corresponding to the request 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 | Indicates a specific behavior expected from the server | Expect: 100-continue |
| From | The email address of the user making the request | From: user@jsons.cn |
| Host | Specifies the domain name and port number of the requested server | Host: www.jsons.cn |
| If-Match | Only processes the request if the entity matches the specified value | If-Match: "specific value" |
| If-Modified-Since | The request succeeds only if the requested part has been modified after the specified time; otherwise, a 304 code is returned | If-Modified-Since: Sat, 29 Oct 2010 19:43:31 GMT |
| If-None-Match | Returns a 304 code if the content hasn't changed, using the ETag previously sent by the server to compare with the current ETag | If-None-Match: "specific value" |
| If-Range | If the entity hasn't changed, the server sends only the missing part; otherwise, it sends the entire entity. The parameter is also the 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 | Limits the number of times the message can be forwarded through proxies and gateways | Max-Forwards: 10 |
| Pragma | Used to include implementation-specific directives | Pragma: no-cache |
| Proxy-Authorization | Authorization credentials for connecting to a proxy | Proxy-Authorization: authorization credentials for proxy |
| Range | Requests only a portion of the entity, specifying the range | Range: bytes=500-999 |
| Referer | The address of the previous webpage, from which the current request was made | Referer: http://www.jsons.cn |
| TE | Specifies the transfer encodings the client is willing to accept and whether it supports trailer fields in chunked transfer encoding | TE: trailers, deflate;q=0.5 |
| Upgrade | Specifies the transfer protocol that the server should switch to, if supported | Upgrade: HTTP/2.0, SHTTP/1.3, IRC/6.9, RTA/x11 |
| User-Agent | The User-Agent header contains information about the client making the request | User-Agent: Mozilla/5.0 (Linux; X11) |
| Via | Specifies the intermediary gateways or proxy addresses and the communication protocol | Via: 1.0 fred, 1.1 nowhere.com (Apache/1.1) |
| Warning | Warning information about the message entity | Warn: 199 Miscellaneous warning |
| Header | Description | Example |
|---|---|---|
| Accept-Ranges | Indicates whether the server supports range requests and which types of range requests are allowed | Accept-Ranges: bytes |
| Age | Estimated time (in seconds, non-negative) since the original server's response was cached by the proxy | Age: 12 |
| Allow | Valid request methods for a particular network resource; returns 405 if not allowed | Allow: GET, HEAD |
| Cache-Control | Directs all caching mechanisms on whether to cache the response and what types | Cache-Control: no-cache |
| Content-Encoding | The type of encoding used for compressing the returned content by the web server | Content-Encoding: gzip |
| Content-Language | The language of the response body | Content-Language: en,zh |
| Content-Length | The length of the response body | Content-Length: 348 |
| Content-Location | An alternative location where the requested resource can be found | Content-Location: /index.htm |
| Content-MD5 | MD5 checksum for the returned resource | Content-MD5: MD5 checksum |
| Content-Range | The byte position of this part within the entire returned body | Content-Range: bytes 21010-47021/47022 |
| Content-Type | The MIME type of the returned content | Content-Type: text/html; charset=utf-8 |
| Date | The time at which the original server sent the message | Date: Tue, 15 Nov 2010 08:12:31 GMT |
| ETag | The current value of the entity tag for the requested resource | ETag: "current value of entity tag" |
| Expires | The date and time at which the response expires | 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 a different URL to complete the request or to identify a new resource | Location: http://www.jsons.cn |
| Pragma | Includes implementation-specific directives that apply to any recipient in the response chain | Pragma: no-cache |
| Proxy-Authenticate | Indicates the authentication scheme and parameters applicable to the proxy for this URL | Proxy-Authenticate: Basic |
| Refresh | Used for redirection or when a new resource is created; redirects after 5 seconds (proposed by Netscape, supported by most browsers) | Refresh: 5; url=http://www.jsons.cn |
| Retry-After | Notifies the client to try again after the specified time if the entity is temporarily unavailable | Retry-After: 120 |
| Server | The name of the web server software | Server: Apache/1.3.27 (Unix) (Red-Hat/Linux) |
| Set-Cookie | Sets an HTTP cookie | Set-Cookie: UserID=JohnDoe; Max-Age=3600; Version=1 |
| Trailer | Indicates the presence of header fields at the end of chunked transfer encoding | Trailer: Max-Forwards |
| Transfer-Encoding | The encoding used for transferring the file | Transfer-Encoding: chunked |
| Vary | Indicates to downstream proxies whether to use cached responses or request from the original server | Vary: * |
| Via | Informs the client about the proxy through which the response was sent | Via: 1.0 fred, 1.1 nowhere.com (Apache/1.1) |
| Warning | Indicates potential problems with the entity | Warning: 199 Miscellaneous warning |
| WWW-Authenticate | Indicates the authentication scheme that should be used to access the requested entity | WWW-Authenticate: Basic |
HTTP request headers provide information about the request, response, or other transmitted entities. The HTTP headers are divided into four categories: general headers, request headers, response headers, and entity headers.
Each header field consists of a field name, a colon (:), and a field value.
General headers: These can be used for both requests and responses and are related to the overall message rather than a specific resource or transaction.
Request headers: These allow the client to pass information about itself and the type of response it expects.
Response headers: These provide information about the server and the response it is sending.
Entity headers: These define information about the resource being transferred, and they can be used in both requests and responses.