What is Device Fingerprinting?

Device fingerprinting identifies a browser or device from a bundle of signals without a persistent cookie: User-Agent, screen size, timezone, font list, canvas/WebGL hash, language, OS version. The composite “fingerprint” is matched to known profiles for return visits and fraud detection.

In arbitrage, fingerprinting is used by CPA antifraud, trackers (Fraud Score), and ad platforms against multi-accounting and bot traffic. Anti-detect browsers spoof fingerprint fields to isolate ad accounts.

Uses

Antifraud — many “unique” clicks from one fingerprint.
Attribution — supplement to cookies when IDs are short-lived.
Cloaking — detecting moderation bots by datacenter fingerprints (grey/black).

Limits and regulation

Accuracy is below stable device IDs (IDFA/GAID). Safari and Firefox restrict signals. GDPR/ePrivacy need a legal basis; in the EU fingerprinting is often treated like cookies for consent. Apple bans fingerprinting for tracking under App Store policies.

Ethics

In white-hat arbitrage, on-landing fingerprinting usually serves traffic quality. Hidden collection to bypass moderation is policy violation territory and legal risk.