The Blocker Add-On in Shift helps protect your privacy and security while browsing by preventing tracking technologies that collect personal or device data without your consent. Two major ways it does this are through fingerprinting protection and cross-site cookie blocking.
What is fingerprinting?
Fingerprinting is a tracking method that gathers unique details about your device, browser, and setup to create a “digital fingerprint.”
Even without cookies, this fingerprint can be used to identify and follow you across the web.
Examples of data used in fingerprinting:
- Your screen resolution and system fonts
- Installed browser extensions or plugins
- Device type and operating system
- Time zone, language, or graphics card information
This combination of details is often enough for trackers to identify your device uniquely.
How Blocker protects against fingerprinting
Blocker automatically blocks scripts or sources that use fingerprinting techniques to collect device or browser data. These are identified using trusted filter lists such as EasyPrivacy and other verified sources.
When Blocker detects a fingerprinting attempt:
- The script or request is blocked before it can execute.
- The block is counted toward your total blocked items, including:
- Total blocked items on page/lifetime
- Total blocked trackers on page/lifetime
- Fingerprinting attempts were mitigated or blocked
You’re in control of your privacy preferences — you can disable fingerprinting protection globally, for a specific website, or just for a single page if needed.
Example: If a site requires a blocked script to load properly, you can temporarily disable fingerprinting protection for that site and refresh the page.
Fingerprinting protection works alongside cross-site cookie blocking to keep your browsing private and secure.
What are cross-site cookies?
Cross-site cookies (also called third-party cookies) are small files placed by sites other than the one you’re currently visiting.
They’re often used by advertisers and analytics services to track your activity across multiple websites.
Example: You browse a shopping site for shoes, then later see ads for those exact shoes on another site — that’s cross-site tracking.
How Blocker handles cross-site cookies
Blocker automatically removes cookies from requests to known tracker domains, based on trusted filter lists such as EasyPrivacy and EasyList Cookie List.
This process happens at the network level, ensuring that third-party tracking cookies are never stored or sent, even if a site tries to set them.
When cookies are blocked, they’re included in your Blocker statistics, contributing to:
- Total blocked items on page/lifetime
- Total blocked cookies on page/lifetime
- Bandwidth saved
You can choose to disable cookie blocking globally, for a specific site, or just for a single page if needed.
Example: If a trusted site stops functioning correctly because its login cookie is being blocked, you can disable Blocker for that site and refresh the page.
Essential cookies — such as those needed for sign-ins, preferences, or carts — remain unaffected when they come from the same site you’re visiting.
Fingerprinting protection and cross-site cookie blocking work together to prevent tracking through both device identification and stored cookies — helping keep your browsing private and secure.
Privacy and security benefits
By combining fingerprinting protection and cross-site cookie blocking, Blocker helps:
- Prevent trackers from identifying your device.
- Stop advertisers from following you across sites.
- Reduce unwanted personalized ads.
- Keep your browsing data private within Shift.
These protections work automatically — no setup required.
Tip: You can view or adjust your Blocker settings anytime by clicking the Blocker icon in your Shift toolbar.
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