This month’s Tool in the Spotlight: Pure URL, a Firefox extension that removes tracking query string fields like “utm_source=*” from URLs (the homepage of its creator is over here. NOTE: while, according to the add-on web page, the tools declares to be available under the GPL v3.0, we can’t find the location of its actual source code).
What makes us excited about this add-on is that it automatically modifies and strips all unnecessary query string content (e.g. “utm_source=*” but others as well) from URLs that it encounters while you are browsing. Many sites embed these query string elements in links that they provide in order to track you, their advertisement campaigns, conversion sources, etc.
But these fields are of no use to you and even work against your best interests.
What Pure URL does, is turn a hyperlink like this:
into the more reasonable:
By default, Pure URL treats and removes the following unnecessary query string elements (lifted and modified from the extension’s web page as of writing of this article):
- utm_source, utm_medium, utm_term, utm_content, utm_campaign: spyware fields used by Google Analytics
- yclid: spyware fields used by Yandex
- feature: a useless field used by youtube.com
- fb_action_ids, fb_action_types, fb_ref, fb_source, action_object_map, action_type_map, action_ref_map: spyware fields used by Facebook
- ref, fref, hc_location: tracking fields used by Facebook
- ref_: tracking field used by imdb.com
Pure URL strips out these query string values from hyperlinks by default and lets you specify which others you want it to strip as well (and – but why would you do this – which ones of the above, you want to keep).
One word of caution: it is unclear whether or not it prevents these values from being submitted to servers when you make a request containing these values yourself. In other words: it is unclear whether or not this add-on only modifies your DOM or whether it also modifies your requests. This can be an issue when you click on links containing these values in another program (e.g. e-mail client) which then opens up the page in your browser.
While IvyDNS already protects you against this type of tracking on your end, it is useful to have a multi-layered approach to your online security and privacy. Pure URL is a nice addition to these layers which also prevent the server-side from tracking you through these query string values.
NOTE: we are entirely unaffiliated with whoever produces this tool, we receive no compensation whatsoever from them.