TCP SYN (JA4T)

65535_2-4-8-1-3_1220_9

first seen 2026-06-30 20:40 · last seen 2026-09-01 07:16 · 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 kinds2-4-8-1-3
MSS1220
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
t13d2013h2_a09f3c656075_7f0f34a4126d Match?Exact match in Thumbprint's published controlled catalog captures: safari 26.5.2, safari 26.4, safari 26.6.2, +2 more.The fingerprint page shows the full measured match list. More on the catalog.12
t13d1616h2_86a278354501_eeeea65629604
t13d4412h1_fd39b124ee10_58ed7828516f2
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.1
t13d1513h2_8daaf6152771_eca864cca44a1
t13d1514h2_8daaf6152771_43ade6aba3df1
t13d1515h2_8daaf6152771_a54fffd0eb611
t13d1515h1_8daaf6152771_0a20fe35d3a51

HTTP request (JA4H)

fingerprintco-occurrences
ge20nr09enus_538441e4e116_000000000000_0000000000006
ge20nr10enus_b3034183f430_000000000000_000000000000 Match?Exact match in Thumbprint's published controlled catalog captures: firefox 153.0, firefox 153.0.3, firefox 154.0, +21 more.The fingerprint page shows the full measured match list. More on the catalog.3
ge20nn030000_80b089f68b8e_000000000000_0000000000002
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.2
ge20nn08enus_1945e0741196_000000000000_000000000000 Match?Exact match in Thumbprint's published controlled catalog captures: safari 26.5.2, safari 26.4, safari 26.6.2.The fingerprint page shows the full measured match list. More on the catalog.2
ge20nr13enus_4ca454722327_000000000000_0000000000001
ge20nn11enus_3901d4197baf_000000000000_000000000000 Match?Exact match in Thumbprint's published controlled catalog captures: firefox 154.0, firefox 152.0.5, firefox 153.0.1, +3 more.The fingerprint page shows the full measured match list. More on the catalog.1
ge20nn08engb_1945e0741196_000000000000_0000000000001
ge20nn12enus_6017509bc0fc_000000000000_0000000000001
ge20nn05enus_730e0cd04a06_000000000000_0000000000001

HTTP/2 frames (Akamai)

fingerprintco-occurrences
2:0;3:100;4:2097152;9:1|10420225|0|m,s,a,p Match?Exact match in Thumbprint's published controlled catalog captures: safari 26.5.2, safari 26.5, safari 26.4, +2 more.The fingerprint page shows the full measured match list. More on the catalog.11
1:4096;2:0;4:32768;5:16384|12517377|3:0:0:42|m,p,a,s2
1:4096;2:0;4:32768;5:16384|12517377|3:0:0:22|m,p,a,s2
4:16777216|16711681|0|m,p,a,s2
1:65536;2:0;4:6291456;6:262144|15663105|1:1:0:220|m,a,s,p Match?Exact match in Thumbprint's published controlled catalog captures: chrome 150.0.7871.187, chromium 149.0.7827.102, chrome 149.0.7827.102, +59 more.The fingerprint page shows the full measured match list. More on the catalog.1
1:4096;2:0;4:32768;5:16384|12517377|5:0:0:22|m,p,a,s1
2:0;4:2097152;3:100;9:1|10485760|0|m,s,p,a1

TCP SYN (p0f)

fingerprintco-occurrences
6:54+10:0:1220:65535,9:mss,sok,ts,nop,ws:flow:09
6:47+17:0:1220:65535,9:mss,sok,ts,nop,ws:flow:05
6:49+15:0:1220:65535,9:mss,sok,ts,nop,ws:flow:02
4:47+17:0:1220:65535,9:mss,sok,ts,nop,ws:df,id+:02
6:53+11:0:1220:65535,9:mss,sok,ts,nop,ws:flow:01
6:50+14:0:1220:65535,9:mss,sok,ts,nop,ws:flow:01
6:45+19:0:1220:65535,9:mss,sok,ts,nop,ws:flow:01
4:45+19:0:1220:65535,9:mss,sok,ts,nop,ws:df,id+:01
6:57+7:0:1220:65535,9:mss,sok,ts,nop,ws:flow:01

User-Agent

fingerprintco-occurrences
Mozilla/5.0 (Android 16; Mobile; rv:152.0) Gecko/152.0 Firefox/152.04
Mozilla/5.0 (iPhone; CPU iPhone OS 18_7 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/26.6 Mobile/15E148 Safari/604.14
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/26.6 Safari/605.1.153
Mozilla/5.0 (iPhone; CPU iPhone OS 18_7 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/26.5 Mobile/15E148 Safari/604.12
Mozilla/5.0 (Linux; Android 10; K) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/149.0.0.0 Mobile Safari/537.361
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/90.0.4430.93 Safari/537.361
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/136.0.0.0 Safari/537.361
Harmonic-HN-Android/3.0.1/release1
Mozilla/5.0 (iPhone; CPU iPhone OS 18_7 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/26.4 Mobile/15E148 Safari/604.11
Harmonic-HN-Android/3.0.2/release1

Country

fingerprintco-occurrences
US · United States11
IT · Italy5
NP · Nepal3
AU · Australia1
DE · Germany1
SE · Sweden1
FI · Finland1

Network (ASN)

fingerprintco-occurrences
AS54113 · Fastly, Inc.12
AS12874 · Fastweb SpA4
AS38565 · Ncell Pvt. Ltd.3
AS50304 · Blix Solutions AS1
AS39351 · 31173 Services AB1
AS136557 · Host Universal Pty Ltd1
AS8434 · Telenor Sverige AB1

Cross-transport links

TLS ClientHello fingerprints observed from the same client via the beacon's correlation id on the other transport (e.g. this stack over TCP ↔ that stack over QUIC).

fingerprintlinked observations
q13d0315h3_55b375c5d22e_dc5437974b473
q13d0311h3_55b375c5d22e_653d80c3fe9d1