Compliance & regulatory

Fingerprinting

Identifying users via browser/device signals when cookies are blocked.

Fingerprinting is the technique of identifying a user via browser signals (User-Agent, screen resolution, fonts, canvas hash, WebGL parameters, audio context, etc.) instead of cookies. Used by ad networks, fraud-detection vendors, and affiliate trackers to bridge consent / cookie loss. Apple's ITP and Firefox's TCP block third-party cookies but don't fully block fingerprinting; Apple began rolling out fingerprint-resistance in Safari 17 in 2024.

Example

RedTrack's S2S fallback uses a fingerprint hash when the user's third-party cookie is missing — sustains 60–80% attribution rate on Safari traffic that would otherwise track at zero.

Related terms

Tracker
The system that attributes ad clicks to conversions.
Postback (S2S)
Server-to-server conversion notification.
IVT (Invalid Traffic)
Bot, click-farm, or otherwise non-human ad traffic.
Attribution
Assigning credit for a conversion to the ad touchpoint(s) that drove it.