TLS ClientHello (JA4)

t13d1715h2_5b57614c22b0_a54fffd0eb61

first seen 2026-06-11 00:12 · last seen 2026-10-27 05:39 · 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

t13d1715h2_5b57614c22b0_a54fffd0eb61

Mozilla/5.0 (X11; Linux x86_64; rv:140.0) Gecko/…

User-Agent claims Firefox 140.0

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 (X11; Linux x86_64; rv:140.0) Gecko/20100101 Firefox/140.0
Claimed version	140.0
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

218

2026-06-11

2026-10-27

t13d1715h2_5b57614c22b0_a54fffd0eb61

Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:140…

User-Agent claims Firefox 140.0

TLS extensions or signature algorithms differ from every measured Firefox capture

Full User-Agent	Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:140.0) Gecko/20100101 Firefox/140.0
Claimed version	140.0
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

2026-06-20

2026-10-01

t13d1715h2_5b57614c22b0_a54fffd0eb61

Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv…

User-Agent claims Firefox 140.0

TLS extensions or signature algorithms differ from every measured Firefox capture

Full User-Agent	Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:140.0) Gecko/20100101 Firefox/140.0
Claimed version	140.0
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

2026-07-01

2026-10-25

t13d1715h2_5b57614c22b0_a54fffd0eb61

Mozilla/5.0 (Android 16; Mobile; rv:148.0) Gecko…

User-Agent claims Firefox 148.0

TLS extensions or signature algorithms differ from every measured Firefox capture

Full User-Agent	Mozilla/5.0 (Android 16; Mobile; rv:148.0) Gecko/148.0 Firefox/148.0
Claimed version	148.0
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

2026-06-19

t13d1715h2_5b57614c22b0_a54fffd0eb61

Mozilla/5.0 (X11; Linux x86_64; rv:151.0) Gecko/…

User-Agent claims Firefox 151.0

TLS extensions or signature algorithms differ from every measured Firefox capture

Full User-Agent	Mozilla/5.0 (X11; Linux x86_64; rv:151.0) Gecko/20100101 Firefox/151.0
Claimed version	151.0
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

2026-07-08

t13d1715h2_5b57614c22b0_a54fffd0eb61

Mozilla/5.0 (iPhone; CPU iPhone OS 18_7 like Mac…

User-Agent claims Firefox 148.0

TLS extensions or signature algorithms differ from every measured Firefox capture

Full User-Agent	Mozilla/5.0 (iPhone; CPU iPhone OS 18_7 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) FxiOS/148.0 Mobile/15E148 Safari/605.1.15
Claimed version	148.0
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

2026-06-19

t13d1715h2_5b57614c22b0_a54fffd0eb61

Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:152…

User-Agent claims Firefox 152.0

TLS extensions or signature algorithms differ from every measured Firefox capture

Full User-Agent	Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:152.0) Gecko/20100101 Firefox/152.0
Claimed version	152.0
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

2026-07-01

t13d1715h2_5b57614c22b0_a54fffd0eb61

Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:146.0…

User-Agent claims Firefox 146.0

TLS extensions or signature algorithms differ from every measured Firefox capture

Full User-Agent	Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:146.0) Gecko/20100101 Firefox/146.0
Claimed version	146.0
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

2026-07-14

Last 7 days (16 observations)

Distinct clients per day (last 30 days, peak 6/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

Protocol	`t (TLS over TCP)`
TLS version	`13`
SNI	`d (domain)`
Cipher count	`17`
Extension count	`15`
ALPN	`h2`
Ciphers	`002f, 0035, 009c, 009d, 1301, 1302, 1303, c009, c00a, c013, c014, c02b, c02c, c02f, c030, cca8, cca9`
Extensions	`0005, 000a, 000b, 000d, 0012, 0017, 001b, 001c, 0022, 002b, 0033, fe0d, ff01`
Signature algorithms	`0403, 0503, 0603, 0804, 0805, 0806, 0401, 0501, 0601, 0203, 0201`
JA4_r	`t13d1715h2_002f,0035,009c,009d,1301,1302,1303,c009,c00a,c013,c014,c02b,c02c,c02f,c030,cca8,cca9_0005,000a,000b,000d,0012,0017,001b,001c,0022,002b,0033,fe0d,ff01_0403,0503,0603,0804,0805,0806,0401,0501,0601,0203,0201`
JA4_o (sample)	`t13d1715h2_5b234860e130_1d8d3ca6a7d8`
JA4_ro (sample)	`t13d1715h2_1301,1303,1302,c02b,c02f,cca9,cca8,c02c,c030,c00a,c009,c013,c014,009c,009d,002f,0035_0000,0017,ff01,000a,000b,0010,0005,0022,0012,0033,002b,000d,001c,001b,fe0d_0403,0503,0603,0804,0805,0806,0401,0501,0601,0203,0201`

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
`ge20nr11enus_187a9385d229_000000000000_000000000000`	83
`ge20nr12enus_a72b71f519fc_000000000000_000000000000`	82
`ge20nn12enus_a72b71f519fc_000000000000_000000000000`	79
`ge20nr12enus_a4e537ffe33a_000000000000_000000000000`	19
`ge20nr13enus_47bedc02e943_000000000000_000000000000`	10
`ge20nn13enus_7e820a765fe5_000000000000_000000000000`	8
`ge20nn13enus_47bedc02e943_000000000000_000000000000`	6
`ge20nr13enus_44e1f6d71293_000000000000_000000000000`	6
`ge20nn14enus_f17998ff6631_000000000000_000000000000`	6
`ge20nn030000_6dac75bd47eb_000000000000_000000000000` Match?Exact match in Thumbprint's published controlled catalog captures: python-httpx 0.28.1.The fingerprint page shows the full measured match list. More on the catalog.	4

HTTP/2 frames (Akamai)

fingerprint	co-occurrences
`1:65536;2:0;4:131072;5:16384\|12517377\|3:0:0:22\|m,p,a,s` Match?Exact match in Thumbprint's published controlled catalog captures: firefox 153.0, firefox 153.0.3, firefox 155.0.1, +31 more.The fingerprint page shows the full measured match list. More on the catalog.	81
`1:65536;2:0;4:131072;5:16384\|12517377\|3:0:0:42\|m,p,a,s` Match?Exact match in Thumbprint's published controlled catalog captures: firefox 154.0, firefox 152.0.5, firefox 152.0.1, +3 more.The fingerprint page shows the full measured match list. More on the catalog.	76
`1:65536;2:0;4:131072;5:16384\|12517377\|5:0:0:22\|m,p,a,s` Match?Exact match in Thumbprint's published controlled catalog captures: firefox 153.0.3, firefox 154.0, firefox 153.0, +12 more.The fingerprint page shows the full measured match list. More on the catalog.	16
`1:65536;2:0;4:131072;5:16384\|12517377\|11:0:0:42\|m,p,a,s`	16
`1:65536;2:0;4:131072;5:16384\|12517377\|13:0:0:42\|m,p,a,s`	16
`1:65536;2:0;4:131072;5:16384\|12517377\|7:0:0:22\|m,p,a,s` Match?Exact match in Thumbprint's published controlled catalog captures: firefox 153.0.3, firefox 155.0, firefox 154.0, +3 more.The fingerprint page shows the full measured match list. More on the catalog.	15
`1:65536;2:0;4:131072;5:16384\|12517377\|15:0:0:42\|m,p,a,s`	14
`1:65536;2:0;4:131072;5:16384\|12517377\|17:0:0:42\|m,p,a,s`	12
`1:65536;2:0;4:131072;5:16384\|12517377\|19:0:0:42\|m,p,a,s`	10
`1:65536;2:0;4:131072;5:16384\|12517377\|9:0:0:42\|m,p,a,s`	9

TCP SYN (p0f)

fingerprint	co-occurrences
`6:50+14:0:1440:mss*30,9:mss,nop,nop,ts,nop,ws:flow:0`	21
`6:43+21:0:1440:mss*30,9:mss,nop,nop,ts,nop,ws:flow:0`	19
`6:49+15:0:1440:mss*45,7:mss,sok,ts,nop,ws:flow:0`	17
`6:47+17:0:1440:32768,10:mss,nop,ws,sok,ts:flow:0`	17
`6:59+5:0:1440:mss*30,11:mss,nop,nop,sok,nop,ws:flow:0`	16
`6:47+17:0:1440:mss*45,7:mss,sok,ts,nop,ws:flow:0`	14
`6:54+10:0:1440:mss*45,7:mss,sok,ts,nop,ws:flow:0`	14
`6:45+19:0:1440:mss*45,10:mss,sok,ts,nop,ws:flow:0`	13
`4:51+13:0:1460:mss*44,10:mss,sok,ts,nop,ws:df,id+:0`	12
`4:54+10:0:1460:mss*44,10:mss,sok,ts,nop,ws:df,id+:0`	11

TCP SYN (JA4T)

fingerprint	co-occurrences
`64800_2-4-8-1-3_1440_7`	64
`43200_2-1-1-8-1-3_1440_9`	36
`32768_2-1-3-4-8_1440_10`	30
`64240_2-4-8-1-3_1460_10`	28
`64240_2-4-8-1-3_1460_7`	24
`43200_2-1-1-4-1-3_1440_11`	16
`64800_2-4-8-1-3_1440_10`	13
`65535_2-4-8-1-3_1440_9`	11
`64240_2-1-1-4-1-3_1460_9`	7
`43200_2-1-1-4-1-3_1440_10`	7

User-Agent

fingerprint	co-occurrences
`Mozilla/5.0 (X11; Linux x86_64; rv:140.0) Gecko/20100101 Firefox/140.0`	218
`Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:140.0) Gecko/20100101 Firefox/140.0`	52
`Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:140.0) Gecko/20100101 Firefox/140.0`	33
`Mozilla/5.0 (Android 16; Mobile; rv:148.0) Gecko/148.0 Firefox/148.0`	6
`Mozilla/5.0 (X11; Linux x86_64; rv:151.0) Gecko/20100101 Firefox/151.0`	5
`Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/131.0.0.0 Safari/537.36`	4
`Mozilla/5.0 (iPhone; CPU iPhone OS 18_7 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) FxiOS/148.0 Mobile/15E148 Safari/605.1.15`	2
`Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:152.0) Gecko/20100101 Firefox/152.0`	1
`Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:146.0) Gecko/20100101 Firefox/146.0`	1

Country

fingerprint	co-occurrences
`NL` · Netherlands	58
`DE` · Germany	49
`SE` · Sweden	49
`US` · United States	41
`CA` · Canada	24
`SI` · Slovenia	13
`MD` · Moldova	13
`CH` · Switzerland	12
`NO` · Norway	11
`AU` · Australia	9

Network (ASN)

fingerprint	co-occurrences
`AS215125` · Church of Cyberology	36
`AS60729` · Stiftung Erneuerbare Freiheit	32
`AS11878` · tzulo, inc.	21
`AS209854` · Cyberzone S.A.	20
`AS212238` · Datacamp Limited	19
`AS198093` · Foreningen for digitala fri- och rattigheter	19
`AS62744` · Quintex Alliance Consulting	14
`AS34779` · T-2, d.o.o.	13
`AS43289` · Trabia SRL	13
`AS53667` · FranTech Solutions	12

TLS supported groups

fingerprint	co-occurrences
`11ec,001d,0017,0018,0019,0100,0101`	16

Cross-transport links

TLS ClientHello fingerprints observed from the same client via the beacon's correlation id on the other transport (e.g. this stack over TCP ↔ that stack over QUIC).

fingerprint	linked observations
`q13d0313h3_55b375c5d22e_fc7519ff7bc2`	6
`q13d0314h3_55b375c5d22e_61e396c58b1f`	2