HTTP Headers Parser

HTTP Headers Parser

Our HTTP Headers Parser allows you to explore and understand the HTTP headers sent by a web server. Simply input  the URL into the designated field at the top of the page and click “Parse.”  

The tool can be useful during testing and troubleshooting and can help validating the proper functioning of a web server or applications.

About HTTP Headers

HTTP headers are key components of the HTTP (Hypertext Transfer Protocol) communication between a client (such as a web browser) and a web server. These headers contain metadata or additional information sent along with the actual content in an HTTP request or response. Headers provide important details about the data being transferred, the server, the client, and the communication itself. 

HTTP headers are defined in various standards and RFCs (Request for Comments). The core RFCs for HTTP are RFC 9110,  RFC 9111, RFC 9112.

Here are some key headers that a web server commonly sends in response to a client's request:

Age: Provides the server's estimate of the time in seconds since the response was generated or successfully validated at the origin server.
Example: Age: 250

Cache-Control: Contains directives controlling content caching mechanisms.
Example: Cache-Control: max-age=3600, public

Connection: Lists desired control options for the current connection.
Example:  Connection: keep-alive

Content-Encoding: Specifies the encoding transformations applied to the resource.
Example: Content-Encoding: gzip

Content-Length:  Indicates the size of the response data in octets (bytes).
Example: Content-Length: 1234

Content-Type:  Specifies the media type of the resource being sent.
Example: Content-Type: text/html; charset=utf-8

Date: Represents the date and time when the message was originated.
Example: Date: Thu, 07 Nov 2019 12:00:00 GMT

Expires: Specifies a date and time in the future until which the data should be considered valid.
Example: Expires: Thu, 07 Nov 2019 13:00:00 GMT

Last-Modified: Indicates the last modification date of the data.
Example: Last-Modified: Tue, 15 Oct 2019 10:00:00 GMT

Server: Informs the client about the software used by the origin server.
Example: Server: Apache/2.4.29 (Ubuntu)

Transfer-Encoding: Specifies the form of encoding that has been applied to the message body.
Example: Transfer-Encoding: chunked

The full list of headers with the links to the corresponding references documents can be found in the IANA’s Hypertext Transfer Protocol (HTTP) Field Name Registry.   

Web servers may also include "X-" headers, denoting non-standard or experimental headers. These are frequently utilized to introduce custom metadata to the HTTP request or response.