TCP SYN (JA4T)

65535_2-4-8-1-3_1376_8

first seen 2026-07-26 19:14 · last seen 2026-09-15 06:08 · JSON

Last 7 days (3 observations)

Distinct clients per day (last 30 days, peak 4/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
MSS1376
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
t13d1515h1_8daaf6152771_de4a06bb82e33
t13d1516h2_8daaf6152771_d8a2da3f94cd Match?Exact match in Thumbprint's published controlled catalog captures: chromium 149.0.7827.102, chrome 149.0.7827.102, chrome 149.0.7827.156, +25 more.The fingerprint page shows the full measured match list. More on the catalog.2
t13d3113h2_e8f1e7e78f70_1b3407e2c9362
t13d4412h1_fd39b124ee10_58ed7828516f1
t13d1515h1_8daaf6152771_0a20fe35d3a51
t13d1516h1_8daaf6152771_1a63afa7c4781

HTTP request (JA4H)

fingerprintco-occurrences
ge11nn13enus_9db22d02e17a_000000000000_0000000000005
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, +23 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 8.18.0, +9 more.The fingerprint page shows the full measured match list. More on the catalog.2
ge11nn050000_b223a0ebb0b5_000000000000_000000000000 Match?Exact match in Thumbprint's published controlled catalog captures: python-requests 2.34.2, python-requests 2.33.1, python-requests 2.32.3.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, +43 more.The fingerprint page shows the full measured match list. More on the catalog.2
3:100;4:33554432;2:0|33488897|0|m,p,s,a Match?Exact match in Thumbprint's published controlled catalog captures: php-curl 7.88.1.The fingerprint page shows the full measured match list. More on the catalog.2

TCP SYN (p0f)

fingerprintco-occurrences
6:51+13:0:1376:65535,8:mss,sok,ts,nop,ws:flow:02
6:45+19:0:1376:65535,8:mss,sok,ts,nop,ws:flow:02
4:45+19:0:1376:65535,8:mss,sok,ts,nop,ws:df,id+:01
6:50+14:0:1376:65535,8:mss,sok,ts,nop,ws:flow:01
6:48+16:0:1376:65535,8:mss,sok,ts,nop,ws:flow:01
6:52+12:0:1376:65535,8:mss,sok,ts,nop,ws:flow:01
6:54+10:0:1376:65535,8:mss,sok,ts,nop,ws:flow:01
6:44+20:0:1376:65535,8:mss,sok,ts,nop,ws:flow:01

User-Agent

fingerprintco-occurrences
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/123.0.0.0 Safari/537.362
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/136.0.0.0 Safari/537.362
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/139.0 Safari/537.362
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/104.0.0.0 Safari/537.361
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/99.0.4844.51 Safari/537.361
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/100.0.4896.75 Safari/537.361
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_3) AppleWebKit/537.36 (KHTML, like Gecko) Brave Chrome/86.0.4240.99 Safari/537.361

Country

fingerprintco-occurrences
US · United States7
RU · Russia2
AT · Austria1

Network (ASN)

fingerprintco-occurrences
AS21928 · T-Mobile USA, Inc.7
AS12389 · PJSC Rostelecom1
AS8447 · A1 Telekom Austria AG1
AS25159 · PJSC MegaFon1