TCP SYN (JA4T)

65535_2-4-8-1-3_1452_4

first seen 2026-08-03 17:54 · last seen 2026-10-12 04:00 · JSON

Distinct clients per day (last 30 days, peak 5/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
MSS1452
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
t13d2013h1_2b729b4bf6f3_e24568c0d44023
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.12
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.6

HTTP request (JA4H)

fingerprintco-occurrences
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.23
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.12
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.6

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.12
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.6

TCP SYN (p0f)

fingerprintco-occurrences
4:47+17:0:1452:65535,4:mss,sok,ts,nop,ws:df,id+:09
4:50+14:0:1452:65535,4:mss,sok,ts,nop,ws:df,id+:05
4:51+13:0:1452:65535,4:mss,sok,ts,nop,ws:df,id+:05
4:49+15:0:1452:65535,4:mss,sok,ts,nop,ws:df,id+:05
4:52+12:0:1452:65535,4:mss,sok,ts,nop,ws:df,id+:04
4:53+11:0:1452:65535,4:mss,sok,ts,nop,ws:df,id+:04
4:54+10:0:1452:65535,4:mss,sok,ts,nop,ws:df,id+:03
4:48+16:0:1452:65535,4:mss,sok,ts,nop,ws:df,id+:03
4:56+8:0:1452:65535,4:mss,sok,ts,nop,ws:df,id+:02
4:46+18:0:1452:65535,4:mss,sok,ts,nop,ws:df,id+:01

User-Agent

fingerprintco-occurrences
curl/8.21.023
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/150.0.0.0 Safari/537.3612
curl/8.5.06

Country

fingerprintco-occurrences
US · United States29
CN · China12

Network (ASN)

fingerprintco-occurrences
AS209 · CenturyLink Communications, LLC11
AS7871 · SEI Data, Inc.5
AS13977 · Fidium3
AS56041 · China Mobile communications corporation3
AS56046 · China Mobile communications corporation2
AS21947 · Blackfoot Telephone Cooperative, Inc.2
AS134810 · China Mobile Group JiLin communications corporation2
AS3663 · NetNet2
AS4134 · CHINANET BACKBONE1
AS4837 · CHINA UNICOM China169 Backbone1