User-Agent

Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:137.3) Gecko/20100101 Firefox/137.3

first seen 2026-08-17 22:34 · last seen 2026-08-18 15:27 · JSON

Decomposed attributes

Browser / client	`Firefox 137.3`
Operating system	`Windows 10.0`
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.

TLS ClientHello (JA4)

fingerprint	co-occurrences
`t13d1717h2_5b57614c22b0_3cbfd9057e0d` Match?Exact match in Thumbprint's published controlled catalog captures: firefox 148.0.2, firefox 144.0.2, firefox 142.0.1, +6 more.The fingerprint page shows the full measured match list. More on the catalog.	2
`t13d1716h2_5b57614c22b0_eeeea6562960` Match?Exact match in Thumbprint's published controlled catalog captures: firefox 132.0, firefox 134.0.The fingerprint page shows the full measured match list. More on the catalog.	1
`t13d1513h2_8daaf6152771_748f4c70de1c`	1

HTTP request (JA4H)

fingerprint	co-occurrences
`ge20nn11enus_3901d4197baf_000000000000_000000000000` Match?Exact match in Thumbprint's published controlled catalog captures: firefox 154.0, firefox 152.0.5, firefox 153.0.1, +3 more.The fingerprint page shows the full measured match list. More on the catalog.	3
`ge20nn12enus_a72b71f519fc_000000000000_000000000000`	1

HTTP/2 frames (Akamai)

fingerprint	co-occurrences
`1:65536;2:0;4:131072;5:16384\|12517377\|1:0:0:42\|m,p,a,s`	2
`1:65536;2:0;4:131072;5:16384\|12517377\|1:0:0:256\|m,p,a,s`	2

TCP SYN (p0f)

fingerprint	co-occurrences
`4:47+17:0:1460:mss*44,10:mss,sok,ts,nop,ws:df,id+:0`	1
`4:50+14:0:1460:65535,9:mss,sok,ts,nop,ws:df,id+:0`	1
`4:54+10:0:1460:32768,10:mss,nop,ws,sok,ts::0`	1
`4:52+12:0:8960:mss*7,7:mss,sok,ts,nop,ws:df,id+:0`	1

TCP SYN (JA4T)

fingerprint	co-occurrences
`64240_2-4-8-1-3_1460_10`	1
`65535_2-4-8-1-3_1460_9`	1
`62720_2-4-8-1-3_8960_7`	1
`32768_2-1-3-4-8_1460_10`	1

Country

fingerprint	co-occurrences
`DE` · Germany	2
`NL` · Netherlands	1
`FR` · France	1

Network (ASN)

fingerprint	co-occurrences
`AS60729` · Stiftung Erneuerbare Freiheit	1
`AS215125` · Church of Cyberology	1
`AS205100` · F3 Netze e.V.	1
`AS213873` · OUIDO Hosting	1