TCP SYN (JA4T)

64240_2-4-8-1-3_1380_10

first seen 2026-07-01 14:41 · last seen 2026-10-12 08:53 · JSON

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

TCP window64240
Option kinds2-4-8-1-3
MSS1380
Window scale10

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)

fingerprintco-occurrences
t13d1715h2_5b57614c22b0_a54fffd0eb616
t13d1617h2_86a278354501_3cbfd9057e0d Match?Exact match in Thumbprint's published controlled catalog captures: firefox 153.0, firefox 153.0.3, firefox 152.0.3, +10 more.The fingerprint page shows the full measured match list. More on the catalog.4
t13d1517h2_8daaf6152771_3cbfd9057e0d Match?Exact match in Thumbprint's published controlled catalog captures: firefox 155.0.1, firefox 154.0, firefox 156.0, +8 more.The fingerprint page shows the full measured match list. More on the catalog.3
t13d1312h2_f57a46bbacb6_ab7e3b40a677 Match?Exact match in Thumbprint's published controlled catalog captures: go-net/http 1.26.6, go-net/http 1.26.10, go-net/http 1.26.9, +7 more.The fingerprint page shows the full measured match list. More on the catalog.2
t13d1714h2_5b57614c22b0_53a6d0ab1c422
t13d491100_bd868743f55c_fa269c3d986d2
t13d1616h2_86a278354501_0c27189014cf Match?Exact match in Thumbprint's published controlled catalog captures: firefox 153.0, firefox 153.0.3, firefox 152.0.6, +10 more.The fingerprint page shows the full measured match list. More on the catalog.1

HTTP request (JA4H)

fingerprintco-occurrences
ge20nr11enus_187a9385d229_000000000000_0000000000004
ge20nr11ruru_3901d4197baf_000000000000_0000000000004
ge20nr12enus_a72b71f519fc_000000000000_0000000000003
ge20nr11enus_1d88e8a431b9_000000000000_0000000000003
ge11nn100000_d871a5d9265f_000000000000_0000000000002
ge20nn12enus_a72b71f519fc_000000000000_0000000000001
ge20nn030000_80b089f68b8e_000000000000_0000000000001
ge20nr030000_80b089f68b8e_000000000000_0000000000001
ge20nr10ruru_d353d425b0bb_000000000000_0000000000001

HTTP/2 frames (Akamai)

fingerprintco-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, +32 more.The fingerprint page shows the full measured match list. More on the catalog.5
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.4
2:0;4:4194304;5:16384;6:10485760|1073741824|0|a,m,p,s Match?Exact match in Thumbprint's published controlled catalog captures: go-net/http 1.26.6, go-net/http 1.26.10, go-net/http 1.26.9, +8 more.The fingerprint page shows the full measured match list. More on the catalog.2
1:65536;2:0;4:131072;5:16384|12517377|7:0:0:42|m,p,a,s2
1:65536;2:0;4:131072;5:16384|12517377|5:0:0:42|m,p,a,s2
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, +13 more.The fingerprint page shows the full measured match list. More on the catalog.1
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 158.0.1, firefox 155.0, +4 more.The fingerprint page shows the full measured match list. More on the catalog.1
1:65536;2:0;4:131072;5:16384|12517377|11:0:0:42|m,p,a,s1

TCP SYN (p0f)

fingerprintco-occurrences
4:47+17:0:1380:mss*44,10:mss,sok,ts,nop,ws:df,id+:013
4:48+16:0:1380:mss*44,10:mss,sok,ts,nop,ws:df,id+:05
4:51+13:0:1380:mss*44,10:mss,sok,ts,nop,ws:df,id+,ecn:01
4:52+12:0:1380:mss*44,10:mss,sok,ts,nop,ws:df,id+,ecn:01

User-Agent

fingerprintco-occurrences
Mozilla/5.0 (X11; Linux x86_64; rv:140.0) Gecko/20100101 Firefox/140.08
Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:152.0) Gecko/20100101 Firefox/152.05
Mozilla/5.0 (X11; Linux x86_64; rv:157.0) Gecko/20100101 Firefox/157.03
LinkedInBot/1.0 (compatible; Mozilla/5.0; Apache-HttpClient +http://www.linkedin.com)2
ShopifyDomainScanner/2.0 (+dataset classification)2

Country

fingerprintco-occurrences
DK · Denmark11
RU · Russia5
US · United States2
SE · Sweden2

Network (ASN)

fingerprintco-occurrences
AS3292 · TDC Holding A/S11
AS29124 · Iskratelecom JSC5
AS9009 · M247 Europe SRL2
AS40793 · LinkedIn Corporation2

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).

fingerprintlinked observations
q13d0315h3_55b375c5d22e_dc5437974b473