What is my FLoC Cohort ID?
Updated at: Feb 25, 2022
This page shows you your FLoC Cohort Identifier - if it's possible to detect it.
What was FLoC?
FLoC was an experiment by Google to find a new way to perform targetted advertising (or "interest based advertising") without relying on Third-Party Cookies (which many users now choose to disable).
In other words...
Internet advertising companies want to show you ads tailored to your personal demographics, interests, and buying habits as these tend to be the most effective kind.
In the past, advertising companies relied heavily on browser cookies (particularly third-party cookies) to track your browsing activity across the internet and determine the kinds of demographics that you fall into and the interests you probably have.
The problem that advertisers are facing now is that a lot of privacy-focused web browsers such as Firefox and Safari have started to disable cookies by default, rendering advertiser's main method of tracking users and their interests ineffective.
FLoC was a different approach to showing you relevant ads
A third-party cookie - as used by advertising companies - is like a little unique identifer token, which it gives you and then uses to track you across all the sites you visit (and which it runs ads on). The token doesn't actually "mean" anything per se, it's just a bit of data which identifies a single user/browser. The meaning comes from tracking where that identifier appears in different places on the web. So the advertising company might see your identifer on website 1, and then a few minutes later it sees the same identifier on website 2, and so the advertising company knows the same person is browsing those two pages and can start to build a profile about you personally.
FLoC is different - the idea behind FLoC is that as you browse the internet, your web browser analyses all of the different web sites that you view; and then over time it starts to figure out the sorts of things that you are interested in. Your web browser then groups you into a "cohort", which is identified by a number. As you view more web sites, advertisers can look at your Cohort ID and use it to determine what advertising categories might be most relevant to you.
What was a Cohort?
A "cohort" is a group of users with "similar browsing histories". As you browse the web, browsers which support FLoC (Currently, this is only Google Chrome), will analyse your browsing history and over time determine which cohort ID defines your browsing history best.
A Cohort ID is a decimal number, eg 15977 which indicates the cohort you currently belong to. As you browse the web, your cohort will most likely change over time.
How am I grouped into a Cohort?
As you browse the web, your web browser analyses your browsing traffic and determines, based on the domain names (not the actual pages you visit on the site) which cohort ID suits you best.
What is a cohort version number?
The algorithm that groups users into cohorts works is presumed to change over time, so a Cohort ID requires a version number as well. Otherwise, the meaning of a particular Cohort ID could change over time and advertisers would no longer know what it actually refers to - having a version number for a cohort ID lets them say "ID 12345 in FLoC version 1.1 means abc, but the same ID 12345 in FLoC version 2.1 means xyz".
The version number also includes a fragment that states the browser/algorithm that generated the Cohort ID - this suggests that there might end up being more than one algorithm which generates Cohort IDs.
Browser support for FLoC
Google Chrome was the only browser which supported FLoC, and even then it was only in a special "experimental mode".
Google have since stopped developing and using FLoC.
The Verge: Google abandons FLoC, introduces Topics API to replace tracking cookies
A number of web browsers have already announced that they won't support or implement FLoC.
- Why Brave disables FLoC
- Vivaldi users will not get FLoC
- DuckDuckGo will block FLoC
- The Verge: Nobody is flying to join Google’s FLoC
A number of websites have also announced that they won't be using FLoC to target advertising to their customers.
Privacy concerns with FLoC?
A number of groups have raised concerns with FLoC being used to profile and identify users.
