Understanding tracking with

How it works

On you can consult information about cookies, Local Storage, pixels and other tracking technologies. You can also read the Data Passports we created about the services and organizations that create or use these technologies.


Contributors to and moderators of this database are the more than 700000 websites using for Consent Management.

Popular Data Passports

Google Analytics is a web analytics service offered by Google that tracks and reports website traffic.

TikTok is a Chinese video-sharing social networking service owned and served worldwide by Bytedance.

YouTube is an American online video sharing and social media platform launched in February 2005.

Facebook is an American online social media and social networking service owned by Meta Platforms, Inc

AddThis is a social bookmarking service that can be integrated into a website with the use of a web widget.

Yoast SEO is a search engine optimization (SEO) plug-in for WordPress owned by Newfold Digital.

About is a project that started in 2019, and that wants to bring more transparency in the online world of website tracking and collecting personal data.

Almost everybody gets targeted through the use of cookies and other online techniques. Often, the function and the duration they stay active are unknown to websitevisitors.

We want to change this by describing the consequences for data privacy, per service, and per cookie. To do this, we continually research and moderate cookie details and the services that place these cookies.

In the first two weeks since  the start of the project, more than 5000 different cookies were added by our users!  

Developing the Data passports

In the second stage of the project (2021), we wanted to understand what a company actually knows about website visitors when combining the data they get from different cookies and services. This is why we created the Data Passports. They are based on the information from public sources, such as the privacystatement of a vendor.

Sponsoring and partnerships

This project is financially supported by Complianz, a Privacy Suite for WordPress, and by SIDN Fund, a Dutch foundation focussing on user empowerment and an inviolable internet for all.

We are always open to new sponsor proposals, or to organizations that want to cooperate with us in other (non-financial) ways, in order to keep up to date and available for free. 


By using the search function, everybody can use the data from the cookie database. The database also makes it possible to translate the descriptions of the cookies in all languages.

The data in the cookie database can be used freely under the Attribution-NonCommercial-NoDerivatives-4.0-International License 

Contributed Cookies
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Synced Websites
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Do you have extra information about a service or cookie? Let us know!

  • A cookie function describes the exact function of the individual cookie. A Purpose describes the Why behind the function.
  • If a known cookie is related to this function. Please enter the name here.
  • If a known service and/or vendor is related to this function. Please enter the name here.
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