TCP SYN (JA4T)

65535_2-4-8-1-3_1440_4

first seen 2026-08-03 17:55 · last seen 2026-10-14 04:14 · JSON

Distinct clients per day (last 30 days, peak 2/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
MSS1440
Window scale4

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
t13d1516h2_8daaf6152771_806a8c22fdea Match?Exact match in Thumbprint's published controlled catalog captures: chrome 150.0.7871.187, chrome 151.0.7922.137, chromium 151.0.7922.34, +28 more.The fingerprint page shows the full measured match list. More on the catalog.4
t13d2013h1_2b729b4bf6f3_e24568c0d4402
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
ge20nn13enus_0c2c1d640f3e_000000000000_000000000000 Match?Exact match in Thumbprint's published controlled catalog captures: chrome 151.0.7922.137, chrome 151.0.7922.170, chrome 151.0.7922.108, +39 more.The fingerprint page shows the full measured match list. More on the catalog.4
ge11nn030000_fe444ad14866_000000000000_000000000000 Match?Exact match in Thumbprint's published controlled catalog captures: curl 8.16.0, curl 7.88.1, curl 8.21.0, +1 more.The fingerprint page shows the full measured match list. More on the catalog.2
ge20nn020000_5594a17e7e7e_000000000000_000000000000 Match?Exact match in Thumbprint's published controlled catalog captures: curl 8.7.1, curl 8.5.0, curl 8.13.0, +11 more.The fingerprint page shows the full measured match list. More on the catalog.1

HTTP/2 frames (Akamai)

fingerprintco-occurrences
1:65536;2:0;4:6291456;6:262144|15663105|1:1:0:256|m,a,s,p Match?Exact match in Thumbprint's published controlled catalog captures: chromium 131.0.6778.33, chromium 151.0.7922.34, chrome 151.0.7922.137, +60 more.The fingerprint page shows the full measured match list. More on the catalog.4
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
4:48+16:0:1440:65535,4:mss,sok,ts,nop,ws:df,id+:03
4:55+9:0:1440:65535,4:mss,sok,ts,nop,ws:df,id+:01
4:50+14:0:1440:65535,4:mss,sok,ts,nop,ws:df,id+:01
4:46+18:0:1440:65535,4:mss,sok,ts,nop,ws:df,id+:01
4:41+23:0:1440:65535,4:mss,sok,ts,nop,ws:df,id+:01

User-Agent

fingerprintco-occurrences
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/150.0.0.0 Safari/537.364
curl/8.21.02
curl/8.5.01

Country

fingerprintco-occurrences
CN · China4
US · United States3

Network (ASN)

fingerprintco-occurrences
AS4837 · CHINA UNICOM China169 Backbone2
AS56041 · China Mobile communications corporation1
AS56046 · China Mobile communications corporation1
AS395846 · Direct Communications Rockland, Inc1
AS19008 · Perry-Spencer Communications, Inc.1
AS395948 · ELEKTRAFI INC.1