Ask HN: Except cookies which parameter is sent in every HTTP request? - dedalus
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BjoernKW
Even cookies aren't required (see
[https://tools.ietf.org/html/rfc2616](https://tools.ietf.org/html/rfc2616) and
[https://serverfault.com/questions/163511/what-is-the-
mandato...](https://serverfault.com/questions/163511/what-is-the-mandatory-
information-a-http-request-header-must-contain) for an explanation). It
entirely depends on the client and convention.

That said, browsers typically send headers such as ACCEPT, REFERER and
USER_AGENT (see [https://www.whatismybrowser.com/detect/what-http-headers-
is-...](https://www.whatismybrowser.com/detect/what-http-headers-is-my-
browser-sending) for a complete list of headers for your browser).

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prostanac
The HTTP/1.1 RFC[0] specifies that the host header MUST be included in each
request.

    
    
       >A client MUST include a Host header field in all HTTP/1.1 request
       >messages . If the requested URI does not include an Internet host
       >name for the service being requested, then the Host header field MUST
       >be given with an empty value. An HTTP/1.1 proxy MUST ensure that any
       >request message it forwards does contain an appropriate Host header
       >field that identifies the service being requested by the proxy. All
       >Internet-based HTTP/1.1 servers MUST respond with a 400 (Bad Request)
       >status code to any HTTP/1.1 request message which lacks a Host header
       >field.
    

[0]
[https://tools.ietf.org/html/rfc2616#page-128](https://tools.ietf.org/html/rfc2616#page-128)

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imauld
Depends on the client I would imagine. This is what cURL sends by default:

    
    
        > Host: google.com
        > User-Agent: curl/7.54.0
        > Accept: */*

------
taf2
Etag and Last modified since, headers?

