RefControl

RefControl is an extension for Firefox that lets you control what gets sent as the HTTP Referer on a per-site basis.

This can be useful in a number of situations:

Privacy - Perhaps you think webmasters don't have any business knowing where you found the link to their site. You can configure RefControl to not send the referrer to any site except for ones you explicitly list.
Broken sites - Some sites perform misguided referrer checks in the name of "security". These checks don't add any real security since the referrer is easily faked and can often cause problems when the browser's behavior changes. You can configure RefControl to send these sites whatever they are expecting and work around this kind of problem.
Fun - 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 RefControl will let you do it anyway.

Get RefControl v0.8.16 (75K).

What's new in v0.8.16:

Mark as compatible with Firefox 10
Change the statusbar icon into a toolbar button. It can now be moved from the add-on bar if desired
Fixed encoding problem fi-FI locale which was preventing the options dialog from loading

Full ChangeLog

Screenshot:

Instructions:

You create a list of sites, and the referrer that should be sent for each site. To adjust settings for a single site, use the name of that site in the list (for instance www.example.com).

If you use example.com in the site list then the action will apply to all sites in the example.com domain (mail.example.com, images.example.com, etc.). More specific items in the list take precedence. Assume the following settings:

Site	Action
example.com	<Block>
www.example.com	<Forge>

Then the referrer will be forged for requests to www.example.com and it will be blocked for requests to all other example.com sites.

For the referrer, the following options are available:

Normal - send the referrer as it would normally be sent without interference from RefControl.
Block - send no referrer to this site.
Forge - send the root of the site as the referrer. In the above screenshot, all pages from www.example.net will use http://www.example.net/ as the referrer.
Custom - type in any string and RefControl will use that as the referrer. You can use variables in this string.

There is also a checkbox 3rd Party requests only. If this box is checked, the option selected above will take effect only for 3rd Party requests (when the site is not the same as the referring site). Examples:

Page With Link	Page Linked To	3rd Party Request?
http://www.example.com/	http://www.example.net/	Yes
http://www.example.com/	http://images.example.com/	Yes
http://www.example.net/	http://www.example.net/page2.html	No

Additionally, you can specify the default behavior for any site not in the list. You can set this to something other than Normal if you want to be more protective about your privacy. Setting it to Block for 3rd Party requests only is a fairly good compromise between privacy and not breaking sites. If you change the default behavior and then want a site to get sent the actual referrer, add it to the list and set it to Normal.

Testing:

There's a test page which will display the referrer that was sent by your browser. You can use this to test your installation and settings.

If you want to see the referrer that Firefox sent for a page, you can enable the status bar display. There are two options:

None - Nothing will appear in the statusbar at all.
Referer - The Referer will be displayed directly in the status bar, possibly trimmed if it is long. Hovering over this with the mouse will show the full Referer in a tooltip.

If you'd rather not use the status bar display, you can also right click on the page and select "View Page Info". Then, on the General tab, look for Referring URL.

Contact: refcontrol <AT> stardrifter.org