TCP SYN (JA4T)

65535_2-1-3_1440_8

first seen 2026-10-23 21:44 · last seen 2026-10-23 22:42 · JSON

Distinct clients per day (last 30 days, peak 81/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 kinds2-1-3
MSS1440
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
t13d3013h2_1d37bd780c83_8537cf56674e82

HTTP request (JA4H)

fingerprintco-occurrences
ge20nn030000_bf75ddd0bb29_000000000000_00000000000082

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.82

TCP SYN (p0f)

fingerprintco-occurrences
6:48+16:0:1440:65535,8:mss,nop,ws:flow:027
6:49+15:0:1440:65535,8:mss,nop,ws:flow:026
6:47+17:0:1440:65535,8:mss,nop,ws:flow:011
6:54+10:0:1440:65535,8:mss,nop,ws:flow:08
6:51+13:0:1440:65535,8:mss,nop,ws:flow:05
6:46+18:0:1440:65535,8:mss,nop,ws:flow:02
6:50+14:0:1440:65535,8:mss,nop,ws:flow:02
6:52+12:0:1440:65535,8:mss,nop,ws:flow:01

User-Agent

fingerprintco-occurrences
curl/8.14.182

Country

fingerprintco-occurrences
DE · Germany42
NL · Netherlands16
FR · France9
US · United States8
GB · United Kingdom7

Network (ASN)

fingerprintco-occurrences
AS16276 · OVH SAS64
AS12876 · Scaleway SAS16
AS21100 · ROUTE 95 LLC2

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.82