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Further Readings

Excluded Fields

URL fields that ClearURLs deliberately keeps because websites need them.

Some fields are absolutely required by a page to function correctly. However, these fields may also contain tracking elements. In such cases, we only have the choice between preventing tracking and a functioning service. Below we list all the fields not included in the official rules because they have caused problems in the past.

Site / ServiceFieldDescription
GooglehlRequired for the correct display of Google in different languages
GooglegbvRequired for Google, when visiting without JavaScript
GoogleclientRequired for asynchronous requests to the API
GooglestickRequired for "People also search for" on Google search
GooglezxRequired for serveral Google services (Hangout, GMail Mailenvelope, etc.)
AmazonsRequired for sort search results by "Featured", "Price: Low to High", "Price: High to Low", "Avg. Customer Review" and "Newest Arrivals" (is only not filtered on Amazons search page)
AmazonpscRequired to link to an article, which is available in different versions (e.g., color or size)
AmazonSubscriptionIdRequired for subscriptions
Amazon SearchkeywordsAmazon search can loop without this field. See #55
Cloudflare__cf_chl_jschl_tk__Require by Cloudflare to verify, that an user successfully passes a IUAM/JS Challenge or Captcha
Cloudflare__cf_chl_captcha_tk__Require by Cloudflare to verify, that an user successfully passes a IUAM/JS Challenge or Captcha
backcountry.comskidRequired to link to an article, which is available in different versions (e.g., color or size)
backcountry.comfskidRequired to link to an article, which is available in different versions (e.g., color or size)
AdobecidUsed by Adobe for tracking, but also required by many websites for correct functioning. This rule has been temporarily removed until a whitelist feature is available
TikToklanguageIs no tracking and is required for the website, e.g., the profile view
Facebookcomment_idRequired for comments
FacebookfbidRequired by many different functions. Used mainly as internal ID and not for external tracking
aliexpresspvidRequired for filtering search results
taobao.comuser_number_idRequired for store frontpage (unique ID for specified store)
Twitter redirectstIs required for redirect URLs inside of Twitter mails (!21)
Firefox accountscontextIs required for Firefox Sync (!135)
Google SearchclientFirefox and other browsers use this as an affiliate code. However, since this information is already accessible to Google via the User-Agent HTTP header, it does not provide any privacy benefits—only a loss of revenue for browser manufacturers.
Google SearchsclientUsed by Google to indicate the search client in use. For example, sclient=gws-wiz signifies that the Google Web Search Wizard is being used for the search.