HTTP referrer

HTTP referer

In HTTP, "Referer" is an optional HTTP header field that identifies the address of the web page from which the resource has been requested. By checking the referrer, the server providing the new web page can see where the request originated. In the most common situation, this means that when a user clicks a hyperlink in a web browser, causing the browser to send a request to the server holding the destination web page, the request may include the Referer field, which indicates the last page the user was on. Web sites and web servers log the content of the received Referer field to identify the web page from which the user followed a link, for promotional or statistical purposes. This entails a loss of privacy for the user and may introduce a security risk. To mitigate security risks, browsers have been steadily reducing the amount of information sent in Referer. Continued in Wikipedia

Referer header - HTTP | MDN - MDN Web Docs

The HTTP Referer request header contains the absolute or partial address from which a resource has been requested. The Referer header allows a server to identify referring pages that people are visiting from or where requested resources are being used. This data can be used for analytics, logging, optimized caching, and more.

• Referrer-Policy header
  The HTTP Referrer-Policy response header controls how much referrer information (sent with the Referer header) should be included with requests. Aside from the HTTP header, you can set this policy in HTML.

HTTP referer - Wikipedia

In HTTP, "Referer" (a misspelling of "Referrer") is an optional HTTP header field that identifies the address of the web page (i.e., the URI or IRI) from which the resource has been requested. By checking the referrer, the server providing the new web page can see where the request originated.

HTTP headers | Referer - GeeksforGeeks

The HTTP Referer header is a request-type header that identifies the address of the previous web page, which is linked to the current web page or resource being requested.

Referer - Expert Guide to HTTP headers

Understand how the Referer header identifies the linking page in HTTP requests. Analytics, access control, privacy risks, and Referrer-Policy interaction.

How to use $_SERVER['HTTP_REFERER'] correctly in php?

The referer is a user provided value and shouldn't be relied on as it can be manipulated or omitted at all. Instead use sessions, set a session variable on page1.php and check for it on page2.php.

How to Use the HTTP Referer - ThoughtCo

The HTTP referer is data provided by the web browser that tells you where the person viewing your page has come from. Here's how to get it and use it.

Request Headers in the HTTP protocol

HTTP Request fields These header lines are sent by the client in a HTTP protocol transaction. All lines are RFC822 format headers.

Referrer Policy - World Wide Web Consortium (W3C)

The header name does not share the HTTP Referer header's misspelling. §5 Integration with Fetch and §6 Integration with HTML describe how the Referrer-Policy header is processed.

Referer header: Privacy and security concerns - MDN

There are privacy and security risks associated with the Referer HTTP header. This article describes them, and offers advice on mitigating those risks.

Whats My Referer | Check Your HTTP Referer, IP & User Agent

Instantly check your HTTP referer, public IP address, and browser user agent. Fast, free, and easy to use.