Session ID / Fingerprint Hashing
How visits get counted without collecting anyone’s personal details.
Fingerprint hashing is a technique that creates a temporary, anonymous session identifier by running non-personal attributes — the visitor’s IP address, browser user agent, and a daily rotating salt (a random value that changes every 24 hours) — through a one-way hash function. The result is a scrambled ID that cannot be reversed to identify an individual, and that resets every day.
The practical purpose is simple: your analytics need some way to tell that five page views belong to one visit rather than five different people, or your visitor counts and session metrics would be meaningless. Fingerprint hashing solves that counting problem while collecting no names, no emails, and no other personal details — and the raw IP address that feeds the hash is never stored.
In Crafty Meerkat, fingerprint hashing is how sessions are identified on the Starter plan, and it serves as an automatic fallback whenever a persistent visitor ID is not available. It is also what powers visitor names: friendly labels like “Dashing Falcon” are generated deterministically from the anonymous hash, so the same visitor appears under the same name in your dashboard.
How it works
A one-way hash works like a paper shredder with a consistent pattern: the same inputs always produce the same output, but you cannot reconstruct the inputs from the output. During a given day, the same visitor on the same device produces the same hash, so their page views group into sessions correctly. At midnight the salt rotates, every hash changes, and yesterday’s identifiers become unlinkable to today’s.
That daily reset is the key trade-off. Fingerprint hashing counts visits and sessions accurately within a day, but it cannot recognize Tuesday’s visitor when they return on Thursday. For the full picture — new vs returning visitors, multi-day customer journeys, and accurate unique counts across days — Growth and Agency plans (and every 30-day free trial) use a persistent first-party visitor ID instead, scoped to your site only. That richer data is also what the AI Advisor draws on for better recommendations.
Tips from the den
- ◆If your dashboard shows the same person as a “new” visitor on different days, you are seeing the daily hash rotation on Starter — expected behavior, not a bug.
- ◆Comparing week-over-week unique visitors is most accurate with the persistent visitor ID on Growth and Agency plans, since daily hashes cannot connect a visitor across days.
- ◆Visitor names come from the same anonymous hash, so you can follow a visitor’s session in the live feed without any personal data being involved.
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Common questions
Can a fingerprint hash be traced back to a person?
No. The hash is one-way — it cannot be reversed to recover the IP address or any other input — and it includes a salt that rotates daily, so even the hash itself stops matching after 24 hours. No names, emails, or other personal details go into it, and the raw IP address is never stored.
How is fingerprint hashing different from a persistent visitor ID?
Fingerprint hashing produces a temporary identifier that resets every day, so it counts sessions well but cannot recognize returning visitors across days. A persistent first-party visitor ID (used on Growth and Agency plans) is stable across visits, unlocking new-vs-returning breakdowns, multi-day journeys, and accurate unique counts. Either way, no personal details are collected.
Why do my Starter unique visitor numbers differ from multi-day totals elsewhere?
Because the daily hash rotation means the same person visiting on three different days is counted as three visitors on Starter. Tools using persistent identifiers would count them once. Within any single day, the counts are directly comparable; across days, the persistent visitor ID on Growth and Agency plans gives the deduplicated number.
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