Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:139.0) Gecko/20100101 Firefox/139.0
first seen 2026-07-02 22:53 · last seen 2026-09-14 23:29 · JSON
Last 7 days (1 observations)
Distinct clients per day (last 30 days, peak 1/day)
Distinct clients are counted by IP-hash per complete UTC day — unlike observation counts this is insensitive to one chatty client, but NAT merges clients and address rotation splits them.
Decomposed attributes
Browser / client
Firefox 139.0
Operating system
macOS 10.15
Device class
desktop
Note
inferred from the self-declared string — a claim, not a measurement; compare with the wire fingerprints above
Co-observed signals
Signals from other families seen in the same observation. A fingerprint spread thinly across many lower-layer signatures is a classic inconsistency signal.