TCP SYN (JA4T)

65340_2-4-8-1-3_1452_10

first seen 2026-07-05 13:47 · last seen 2026-10-20 09:46 · 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 window65340
Option kinds2-4-8-1-3
MSS1452
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
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
t13d1516h2_8daaf6152771_0c27189014cf Match?Exact match in Thumbprint's published controlled catalog captures: firefox 154.0, firefox 155.0.1, firefox 155.0, +4 more.The fingerprint page shows the full measured match list. More on the catalog.1
t13d1517h2_8daaf6152771_cb7bf5808d99 Match?Exact match in Thumbprint's published controlled catalog captures: chrome 152.0.7977.83, chrome 154.0.8037.57, chrome 152.0.7977.64, +24 more.The fingerprint page shows the full measured match list. More on the catalog.1

HTTP request (JA4H)

fingerprintco-occurrences
ge20nr11enus_187a9385d229_000000000000_0000000000001
ge20nr12enus_54b4638ab28b_000000000000_000000000000 Match?Exact match in Thumbprint's published controlled catalog captures: chrome 150.0.7871.187, chrome 152.0.7977.83, chrome 151.0.7922.137, +58 more.The fingerprint page shows the full measured match list. More on the catalog.1
ge20nr11enus_1d88e8a431b9_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, +31 more.The fingerprint page shows the full measured match list. More on the catalog.2
1:65536;2:0;4:6291456;6:262144|15663105|1:1:0:220|m,a,s,p Match?Exact match in Thumbprint's published controlled catalog captures: chrome 150.0.7871.187, chromium 149.0.7827.102, chrome 152.0.7977.83, +81 more.The fingerprint page shows the full measured match list. More on the catalog.1

TCP SYN (p0f)

fingerprintco-occurrences
4:50+14:0:1452:mss*45,10:mss,sok,ts,nop,ws:df,id+:03

User-Agent

fingerprintco-occurrences
Mozilla/5.0 (X11; Linux x86_64; rv:152.0) Gecko/20100101 Firefox/152.01
Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:157.0) Gecko/20100101 Firefox/157.01
Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/155.0.0.0 Safari/537.361

Country

fingerprintco-occurrences
ES · Spain2
HU · Hungary1

Network (ASN)

fingerprintco-occurrences
AS3352 · TELEFONICA DE ESPANA S.A.U.2
AS20845 · 2Connect Telecommunications Infrastructure & Network Services Ltd.1

TLS supported groups

fingerprintco-occurrences
0a0a,11ec,001d,0017,0018 Match?Exact match in Thumbprint's published controlled catalog captures: chrome 155.0.8059.40, chrome 156.0.8078.73, chromium 156.0.8078.47, +8 more.The fingerprint page shows the full measured match list. More on the catalog.1
11ec,001d,0017,0018,0019 Match?Exact match in Thumbprint's published controlled catalog captures: firefox 157.0.1, firefox-esr 153.5.1esr, firefox 158.0.1, +3 more.The fingerprint page shows the full measured match list. More on the catalog.1

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_dc5437974b472
q13d0312h3_55b375c5d22e_178839b6cec11