TLS ClientHello (JA4)

t13d1515h2_8daaf6152771_be51d82afabe

first seen 2026-08-19 16:23 · last seen 2026-08-23 17:50 · JSON

Inconsistencies

User-Agents observed with this fingerprint that contradict what it proves at the wire. all inconsistencies →

fingerprint User-Agent claims wire shows confidence seen first seen last seen

t13d1515h2_8daaf6152771_be51d82afabe

Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:133…

User-Agent claims Firefox 133.0

TLS extensions or signature algorithms differ from every measured Firefox capture

The cipher suites match Firefox, but the extension set or signature algorithms differ from every capture even after normalizing handshake-variant extensions. Most likely a field-trial, ECH, or build variant the catalog has not captured; occasionally mimicry. This sharpens as catalog coverage grows.

Full User-Agent	Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:133.0) Gecko/20100101 Firefox/133.0
Claimed version	133.0
Measured versions	146.0.1, 154.0, 140.0.2, 157.0.1, 151.0.2, 155.0, 153.0.3, 142.0.1, 153.0.4, 152.0.6, 150.0.2, 135.0, 156.0.1, 132.0, 152.0.3, 141.0, 153.0, 151.0.3, 156.0, 152.0.4, 151.0, 152.0.1, 151.0.4, 139.0, 153.0.1, 158.0.1, 152.0.5, 157.0, 158.0, 148.0.2, 137.0, 155.0.1, 144.0.2, 154.0.1, 134.0
Layer	cipher suites match; extension set or signature algorithms differ
JA4 label	unlabeled

low

2026-08-19

Decomposed attributes

Protocol	`t (TLS over TCP)`
TLS version	`13`
SNI	`d (domain)`
Cipher count	`15`
Extension count	`15`
ALPN	`h2`
Ciphers	`002f, 0035, 009c, 009d, 1301, 1302, 1303, c013, c014, c02b, c02c, c02f, c030, cca8, cca9`
Extensions	`0005, 000a, 000b, 000d, 0012, 0015, 0017, 001b, 0023, 002b, 002d, 0033, ff01`
Signature algorithms	`0403, 0804, 0401, 0503, 0805, 0501, 0806, 0601, 0201, 0203, 0603`
JA4_r	`t13d1515h2_002f,0035,009c,009d,1301,1302,1303,c013,c014,c02b,c02c,c02f,c030,cca8,cca9_0005,000a,000b,000d,0012,0015,0017,001b,0023,002b,002d,0033,ff01_0403,0804,0401,0503,0805,0501,0806,0601,0201,0203,0603`
JA4_o (sample)	`t13d1515h2_acb858a92679_727605f8b03b`
JA4_ro (sample)	`t13d1515h2_1301,1302,1303,c02b,c02f,c02c,c030,cca9,cca8,c013,c014,009c,009d,002f,0035_0000,0017,ff01,000a,000b,0023,0010,0005,000d,0012,0033,002d,002b,001b,0015_0403,0804,0401,0503,0805,0501,0806,0601,0201,0203,0603`

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.

HTTP request (JA4H)

fingerprint	co-occurrences
`ge20nn13enus_0c2c1d640f3e_000000000000_000000000000` Match?Exact match in Thumbprint's published controlled catalog captures: chrome 151.0.7922.137, chrome 151.0.7922.170, chrome 151.0.7922.108, +36 more.The fingerprint page shows the full measured match list. More on the catalog.	3
`ge20nn07enus_d3a5b8fb805f_000000000000_000000000000`	3
`ge20nn10enus_9fcbd3f1e2d6_000000000000_000000000000`	1

HTTP/2 frames (Akamai)

fingerprint	co-occurrences
`1:65536;2:0;4:6291456;6:262144\|15663105\|0\|m,a,s,p`	3
`2:0;3:100;4:2097152\|10485760\|0\|m,s,p,a`	3
`1:65536;4:131072;5:16384\|12517377\|0\|m,p,a,s`	1

TCP SYN (p0f)

fingerprint	co-occurrences
`4:54+10:0:1460:mss*44,7:mss,sok,ts,nop,ws:df,id+:0`	7

TCP SYN (JA4T)

fingerprint	co-occurrences
`64240_2-4-8-1-3_1460_7`	7

User-Agent

fingerprint	co-occurrences
`Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/18.1 Safari/605.1.15`	3
`Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/131.0.0.0 Safari/537.36`	2
`Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:133.0) Gecko/20100101 Firefox/133.0`	1
`Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/131.0.0.0 Safari/537.36 Edg/131.0.0.0`	1

Country

fingerprint	co-occurrences
`DE` · Germany	7

Network (ASN)

fingerprint	co-occurrences
`AS401626` · Netiface America, Inc.	7

fingerprint	co-occurrences
`1:65536;2:0;4:6291456;6:262144\|15663105\|0\|m,a,s,p`	3
`2:0;3:100;4:2097152\|10485760\|0\|m,s,p,a`	3
`1:65536;4:131072;5:16384\|12517377\|0\|m,p,a,s`	1