TCP SYN (JA4T)

65535_2-1-3-1-1-4_1300_2

first seen 2026-10-14 22:23 · last seen 2026-10-14 22:23 · 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 window65535
Option kinds2-1-3-1-1-4
MSS1300
Window scale2

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
t13d1514h2_8daaf6152771_53a6d0ab1c421

HTTP request (JA4H)

fingerprintco-occurrences
ge20nr11enus_187a9385d229_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.1

TCP SYN (p0f)

fingerprintco-occurrences
4:112+16:0:1300:65535,2:mss,nop,ws,nop,nop,sok:df,id+:01

User-Agent

fingerprintco-occurrences
Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:157.0) Gecko/20100101 Firefox/157.01

Country

fingerprintco-occurrences
EG · Egypt1

Network (ASN)

fingerprintco-occurrences
AS36935 · Vodafone Data1

TLS supported groups

fingerprintco-occurrences
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_dc5437974b471