Supercookies are advanced tracking technologies that persist beyond normal cookies. This guide explains what supercookies are, why they matter, and how they affect online privacy.
What Is Supercookies?
Supercookies are tracking identifiers stored outside traditional browser cookie storage. Unlike standard cookies, they survive cookie deletion and browser resets, which makes them far more persistent.
Traditional cookies rely on browser-managed storage. Supercookies use alternative methods such as browser cache, HTML5 storage, ETags, HSTS flags, or ISP-level injection. Because they are harder to detect and remove, supercookies raise serious privacy and transparency concerns.
From a technical perspective, supercookies are not a single technology. They describe a group of techniques designed to re-identify users across sessions, devices, or networks. Many discussions around supercookies overlap with topics like browser fingerprinting, tracking scripts, and persistent identifiers.
Key Features of Supercookies
- Extreme persistence beyond standard controls
Supercookies are designed to survive actions that normally remove tracking data. Even when users clear browser cookies, reset settings, or switch sessions, supercookies can reappear and continue identifying the same user. - Storage outside traditional cookie locations
Instead of relying on one storage method, supercookies store identifiers across multiple layers, such as browser cache, HTML5 localStorage, ETags, HSTS flags, or service workers. This layered approach makes detection and removal difficult. - Automatic re-identification capability
When a user deletes visible tracking data, supercookies can regenerate standard cookies by pulling data from hidden storage. This process restores the original identifier without user interaction. - Limited user visibility and control
Most browsers do not clearly show where supercookies reside. Users often lack built-in tools to view or manage these identifiers, which reduces transparency and informed consent.
Use Cases of Supercookies
- Long-term advertising attribution
Advertisers use supercookies to track users across extended time periods. This approach helps link ad impressions to conversions even after users delete cookies or change browsers. - Advanced fraud and abuse detection
Financial platforms and online services may use persistent identifiers to detect repeat offenders. Supercookies help identify users who attempt to bypass restrictions through account resets. - Cross-session analytics accuracy
Analytics providers rely on supercookie-style techniques to maintain consistent visitor metrics. This ensures more stable user data when traditional cookies fail or expire. - Network-level user identification
Some ISPs have used supercookies to inject identifiers into HTTP headers. This method allows tracking at the network level rather than through websites alone. - User behavior profiling
Supercookies enable long-term behavior analysis across visits and platforms. This capability supports detailed user segmentation but significantly increases privacy risks.
FAQ
1.What is the difference between a cookie and a supercookie?
A cookie stores data in the browser and is easy to delete. A supercookie uses alternative storage methods and often survives cookie deletion, making it much harder to remove.
2.Are supercookies legal?
Legality depends on jurisdiction. In many regions, supercookies may violate privacy regulations if used without informed user consent, especially under GDPR or similar frameworks.
3.How do we get supercookies?
Users receive supercookies through websites, third-party scripts, or network-level injection. Installation usually happens without clear user awareness.
4.How to get rid of supercookies?
Use privacy-focused browsers, disable third-party scripts, clear advanced storage, and manage network-level tracking. Browser isolation strategies also help reduce exposure.
You May Also Need
Browser Fingerprinting vs Cookies: What’s The Difference?
Antidetect Browser vs Regular Browser: Understanding the Key Differences