TCP SYN (JA4T)

43200_2-4-8-1-3_1440_12

first seen 2026-07-10 12:28 · last seen 2026-10-23 22:34 · JSON

Distinct clients per day (last 30 days, peak 6/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 window43200
Option kinds2-4-8-1-3
MSS1440
Window scale12

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
t13d3013h2_1d37bd780c83_8537cf56674e6
t13d1312h2_f57a46bbacb6_ab7e3b40a677 Match?Exact match in Thumbprint's published controlled catalog captures: go-net/http 1.26.6, go-net/http 1.26.10, go-net/http 1.26.9, +7 more.The fingerprint page shows the full measured match list. More on the catalog.1

HTTP request (JA4H)

fingerprintco-occurrences
ge20nn030000_bf75ddd0bb29_000000000000_0000000000006
ge20nr020000_fb4f949fd323_000000000000_0000000000001

HTTP/2 frames (Akamai)

fingerprintco-occurrences
3:100;4:65536;2:0|1048510465|0|m,s,a,p Match?Exact match in Thumbprint's published controlled catalog captures: curl 8.13.0, curl 8.18.0, curl 8.21.0, +8 more.The fingerprint page shows the full measured match list. More on the catalog.6
2:0;4:4194304;5:16384;6:10485760|1073741824|0|a,m,p,s Match?Exact match in Thumbprint's published controlled catalog captures: go-net/http 1.26.6, go-net/http 1.26.10, go-net/http 1.26.9, +8 more.The fingerprint page shows the full measured match list. More on the catalog.1

TCP SYN (p0f)

fingerprintco-occurrences
6:242+13:0:1440:mss*30,12:mss,sok,ts,nop,ws:flow:01
6:46+18:0:1440:mss*30,12:mss,sok,ts,nop,ws:flow:01
6:48+16:0:1440:mss*30,12:mss,sok,ts,nop,ws:flow:01
6:50+14:0:1440:mss*30,12:mss,sok,ts,nop,ws:flow:01
6:56+8:0:1440:mss*30,12:mss,sok,ts,nop,ws:flow:01
6:53+11:0:1440:mss*30,12:mss,sok,ts,nop,ws:flow:01
6:49+15:0:1440:mss*30,12:mss,sok,ts,nop,ws:flow:01

User-Agent

fingerprintco-occurrences
curl/8.14.16
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/130.0.0.0 Safari/537.361

Country

fingerprintco-occurrences
DE · Germany2
US · United States1
NL · Netherlands1
RO · Romania1
GB · United Kingdom1
NZ · New Zealand1

Network (ASN)

fingerprintco-occurrences
AS9009 · M247 Europe SRL1
AS138997 · Eons Data Communications Limited1
AS18450 · WebNX, Inc.1
AS35042 · Layer7 Networks GmbH1
AS199741 · TransitX BYOIP1
AS202602 · Greencloud LLC1
AS61138 · Zappie Host1

TLS supported groups

fingerprintco-occurrences
11ec,001d,0017,001e,0018,0019,0100,0101 Match?Exact match in Thumbprint's published controlled catalog captures: node-fetch 24.22.1, python-httpx 0.28.1, python-requests 2.34.2, +2 more.The fingerprint page shows the full measured match list. More on the catalog.6