TCP SYN (JA4T)

65535_2-1-3-4-8_1460_9

first seen 2026-08-18 06:24 · last seen 2026-09-07 19:07 · 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 kinds2-1-3-4-8
MSS1460
Window scale9

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
t13d1310h2_a82273826ef7_5603904660151
t13d1411h2_4f2acddecbd5_9ced094328c91
t13d2013h1_2b729b4bf6f3_e24568c0d4401

HTTP request (JA4H)

fingerprintco-occurrences
ge20nn04enus_989c7cc05c9b_000000000000_0000000000002
ge11nn030000_fe444ad14866_000000000000_000000000000 Match?Exact match in Thumbprint's published controlled catalog captures: curl 8.16.0.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;4:1048576|15663105|1:0:0:256|m,a,s,p2

TCP SYN (p0f)

fingerprintco-occurrences
4:53+11:0:1460:65535,9:mss,nop,ws,sok,ts:df:02
4:245+10:0:1460:65535,9:mss,nop,ws,sok,ts::01

User-Agent

fingerprintco-occurrences
curl/8.21.01
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/135.0.0.1 Safari/537.361
Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/124.0.0.1 Safari/537.361

Country

fingerprintco-occurrences
DE · Germany2
US · United States1

Network (ASN)

fingerprintco-occurrences
AS197540 · netcup GmbH2
AS20057 · AT&T Enterprises, LLC1