When an HTML link that references a website is clicked, the web browser will send a request to the server holding the destination webpage / website. Among the request sent by the browser to the referenced website server is the HTTP Referer which indicate the URL of the webpage that referred the user to the site.
Say w3guy.com links to wapden.net, the HTTP referer is the former because it referred the user to the latter.
Below is a screenshot of the request headers sent by the browser to the server, among them is the referer field.
For reason best known to you, you might want to block the referer field from being sent when an external link in your site is clicked.
This can be useful in a number of situations such as:
- Perhaps you think webmasters don’t have any business knowing where you found the link to their site.
- Some sites perform misguided referer checks in the name of “security”. These checks don’t add any real security since the referer is easily faked and can often cause problems when the browser’s behavior changes. You can these sites whatever they are expecting and work around this kind of problem.
- Send humorous things, secure in the knowledge that they are being written into the server’s log file for the amusement of anyone who might later discover them there. Ok, maybe that’s not much fun, but you can do it anyway.
The referer request header field can be hidden via:
- Using a web tool.
- Using browser extension
Using a web tool
There are a lot of online tools that removes / blank out the referer field. An example of such tool is nullrefer.com.
To link anonymously to other web sites without referer, append the link to http://www.nullrefer.com/?.
Say you want to anonymously add a link in your site that leads to https://w3guy.com, the link would be http://nullrefer.com/?https://w3guy.com.
Other similar tools include: HideMyAss, Refhide, anonym.to.
Want to build your own nullrefer.com, refhide.com, href.li alternative, get this PHP script.
You can also incorporate the script to your existing PHP web application.
Using browser extension
There are a couple of Firefox and Chrome browser extensions that removes and spoof HTTP referer.
Firefox
Chrome
There is only one addon i know of for chrome and it is Referer Control.