Ad-Blocker Operation

How Does an Ad-Blocker Work?

An ad-blocker analyzes all requests sent by the web browser and compares them to specific criteria to decide whether they should be blocked. When a request matches these criteria, it is intercepted and blocked before reaching its destination.

Request Evaluation Process

1. Request Inspection: Each HTTP/HTTPS request sent by the browser is examined in real-time.

2. Comparison to Block Lists: The ad-blocker refers to block lists maintained by communities or specialized organizations. These lists, constantly updated, contain rules to identify requests related to tracking and advertising.

Block Lists

Block lists are files that define the criteria for recognizing malicious or undesirable requests. For example, the EasyPrivacy list is often used to block requests related to user tracking. Here’s a link to this list: EasyPrivacy.

Examples of strings in these lists:

• .js?id=GTM-

• googletagmanager.com

• /gtag/js?

These strings primarily target tracking services such as Google Tag Manager and Google Analytics. If no action is taken to avoid blocking, these services will be systematically blocked by ad-blockers.

Updates and Bypasses

Block lists are regularly updated to adapt to new bypass techniques deployed by advertisers or tracking platforms. As a result, innovation in bypassing ad-blockers is a constant challenge. Each new version of the lists requires monitoring and adjustments to restore tracking or advertising functionality.