TCP SYN (JA4T)

65535_2-4-8-1-3_1300_10

first seen 2026-07-12 19:58 · last seen 2026-10-11 22:44 · 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 kinds2-4-8-1-3
MSS1300
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
t13d4312h1_c7886603b240_b26ce05bbdd62
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.1
t13d1515h1_8daaf6152771_0a20fe35d3a51
t13d1313h2_f57a46bbacb6_9249cab70c771

HTTP request (JA4H)

fingerprintco-occurrences
ge11nn050000_b223a0ebb0b5_000000000000_000000000000 Match?Exact match in Thumbprint's published controlled catalog captures: python-requests 2.34.2, python-requests 2.33.1, python-requests 2.32.3.The fingerprint page shows the full measured match list. More on the catalog.2
ge20nn020000_fb4f949fd323_000000000000_000000000000 Match?Exact match in Thumbprint's published controlled catalog captures: powershell 7.6.6, powershell 7.6.9, powershell 7.6.8.The fingerprint page shows the full measured match list. More on the catalog.1
ge11nn14enus_4a2973d235de_000000000000_0000000000001
ge20nn11ruru_3901d4197baf_000000000000_0000000000001

HTTP/2 frames (Akamai)

fingerprintco-occurrences
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.1
1:65536;2:0;3:1000;4:6291456;6:262144|15663105|1:1:0:256|m,a,s,p1

TCP SYN (p0f)

fingerprintco-occurrences
4:50+14:0:1300:65535,10:mss,sok,ts,nop,ws:df,id+:02
4:242+13:0:1300:65535,10:mss,sok,ts,nop,ws:df,id+:01
4:51+13:0:1300:65535,10:mss,sok,ts,nop,ws:df,id+:01
4:43+21:0:1300:65535,10:mss,sok,ts,nop,ws::01

User-Agent

fingerprintco-occurrences
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/124.0.0.0 Safari/537.361
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/146.0.0.0 Safari/537.361
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.361
Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:152.0) Gecko/20100101 Firefox/152.01
Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:127.0) Gecko/20100101 Firefox/127.01

Country

fingerprintco-occurrences
US · United States2
SG · Singapore1
RU · Russia1
GA · Gabon1

Network (ASN)

fingerprintco-occurrences
AS20012 · Interworks Networking Services2
AS25159 · PJSC MegaFon1
AS16058 · Gabon Telecom / Office of Posts and Telecommunications of Gabon1
AS4657 · StarHub Ltd1