Visitor ID
A visitor ID is a stable, unique token derived from a device's fingerprint signals that identifies a returning visitor across sessions. Unlike a cookie, it persists through incognito mode, cookie clearing, and browser restarts because it is computed from the device rather than stored on it.
How Visitor ID works
A visitor ID is produced by an identification algorithm that gathers many device signals, groups them by how stable they are, and combines them into a single token. The token is designed to stay the same for the same device across visits, even as some individual signals drift, so that a returning user is recognized rather than treated as new.
Because the identifier is derived from the device's inherent characteristics, it does not depend on any value written to the browser. Clearing cookies, opening a private window, or wiping local storage removes stored state but does not change the underlying hardware and software profile, so the same visitor ID is recomputed on the next visit.
In practice a visitor ID is returned alongside a confidence score. High confidence means the current signals strongly match a previously seen device; lower confidence signals that the match is uncertain, for example after a major browser update or on a device that closely resembles many others. Consumers use the confidence value to decide how much to trust the identifier.
Why Visitor ID matters for fraud prevention
Persistent recognition is the backbone of fraud prevention. A visitor ID lets a platform link a fraudster's repeat attempts even when they clear cookies between tries, spot one device registering many accounts, and distinguish a trusted returning customer from a first-time visitor. Without a durable identifier, abuse that spans multiple sessions is effectively invisible.
How TRACIO handles it
TRACIO's Identification product returns a visitor ID computed from 130+ device signals, reaching 99.5% accuracy on internal benchmarks. The identifier is engineered to survive incognito mode and cookie clearing, and it is paired with a confidence score so integrators know how strongly to weight it in their own logic.
Frequently asked questions
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