TCP SYN (JA4T)

65535_2-4-8-1-3_1220_8

first seen 2026-07-26 13:42 · last seen 2026-09-07 22:42 · 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
MSS1220
Window scale8

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
t13d1515h1_8daaf6152771_de4a06bb82e33
t13d1515h1_8daaf6152771_0a20fe35d3a52
t13d4412h1_fd39b124ee10_58ed7828516f1
t13d3112h2_e8f1e7e78f70_b26ce05bbdd6 Match?Exact match in Thumbprint's published controlled catalog captures: curl 8.5.0, php-curl 7.88.1.The fingerprint page shows the full measured match list. More on the catalog.1

HTTP request (JA4H)

fingerprintco-occurrences
ge11nn13enus_9db22d02e17a_000000000000_0000000000003
ge11nn14enus_4a2973d235de_000000000000_0000000000002
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.1
ge20nn020000_5594a17e7e7e_000000000000_000000000000 Match?Exact match in Thumbprint's published controlled catalog captures: curl 8.7.1, curl 8.5.0, curl 8.18.0, +9 more.The fingerprint page shows the full measured match list. More on the catalog.1

HTTP/2 frames (Akamai)

fingerprintco-occurrences
3:100;4:10485760;2:0|1048510465|0|m,s,a,p Match?Exact match in Thumbprint's published controlled catalog captures: curl 8.7.1, curl 8.5.0.The fingerprint page shows the full measured match list. More on the catalog.1

TCP SYN (p0f)

fingerprintco-occurrences
4:46+18:0:1220:65535,8:mss,sok,ts,nop,ws:df,id+:02
4:47+17:0:1220:65535,8:mss,sok,ts,nop,ws:df,id+:02
6:55+9:0:1220:65535,8:mss,sok,ts,nop,ws:flow:01
4:48+16:0:1220:65535,8:mss,sok,ts,nop,ws:df,id+:01
4:44+20:0:1220:65535,8:mss,sok,ts,nop,ws:df,id+:01

User-Agent

fingerprintco-occurrences
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/99.0.4844.51 Safari/537.362
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/131.0.0.0 Safari/537.361
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/116.0.0.0 Safari/537.361
curl/8.5.01
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/133.0.0.0 Safari/537.361
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_13_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/80.0.3987.149 Safari/537.361

Country

fingerprintco-occurrences
PL · Poland3
NP · Nepal3
US · United States1

Network (ASN)

fingerprintco-occurrences
AS5617 · Orange Polska Spolka Akcyjna3
AS38565 · Ncell Pvt. Ltd.3
AS7922 · Comcast Cable Communications, LLC1