TCP SYN (JA4T)

65535_2-4-8-1-3_1220_9

first seen 2026-06-30 20:40 · last seen 2026-10-31 14:56 · JSON

Last 7 days (544 observations)

Distinct clients per day (last 30 days, peak 90/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
t13d1518h2_8daaf6152771_4980c97edce01361
t13d3013h2_1d37bd780c83_8537cf56674e59
t13d3013h1_1d37bd780c83_8537cf56674e31
t13d2013h2_a09f3c656075_7f0f34a4126d Match?Exact match in Thumbprint's published controlled catalog captures: safari 26.5.2, safari 26.6.2, safari 26.4, +2 more.The fingerprint page shows the full measured match list. More on the catalog.12
t13d301200_1d37bd780c83_ecd0401ec68b7
t13d1616h2_86a278354501_eeeea65629604
t13d3013h1_1d37bd780c83_ecd0401ec68b2
t13d171000_5b57614c22b0_78e6aca7449b2
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

HTTP request (JA4H)

fingerprintco-occurrences
ge20nr12enus_54b4638ab28b_000000000000_000000000000 Match?Exact match in Thumbprint's published controlled catalog captures: chrome 150.0.7871.187, chrome 152.0.7977.83, chrome 151.0.7922.137, +58 more.The fingerprint page shows the full measured match list. More on the catalog.1092
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, +36 more.The fingerprint page shows the full measured match list. More on the catalog.267
ge20nn020000_5594a17e7e7e_000000000000_000000000000 Match?Exact match in Thumbprint's published controlled catalog captures: curl 8.7.1, curl 8.5.0, curl 8.13.0, +11 more.The fingerprint page shows the full measured match list. More on the catalog.60
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.24
ge11nn040000_5b1e8b5f4d2d_000000000000_0000000000007
ge20nr09enus_538441e4e116_000000000000_0000000000006
ge11nn06enus_fb4afd1f380a_000000000000_0000000000005
ge11nn06en00_fb4afd1f380a_000000000000_0000000000004
ge20nr10enus_b3034183f430_000000000000_000000000000 Match?Exact match in Thumbprint's published controlled catalog captures: firefox 153.0, firefox 153.0.3, firefox 155.0.1, +27 more.The fingerprint page shows the full measured match list. More on the catalog.3
ge20nn030000_80b089f68b8e_000000000000_0000000000002

HTTP/2 frames (Akamai)

fingerprintco-occurrences
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 152.0.7977.83, +81 more.The fingerprint page shows the full measured match list. More on the catalog.535
1:65536;2:0;4:6291456;6:262144|15663105|3:1:0:220|m,a,s,p Match?Exact match in Thumbprint's published controlled catalog captures: chromium 151.0.7922.34, chromium 147.0.7727.15, chromium 145.0.7632.6, +26 more.The fingerprint page shows the full measured match list. More on the catalog.274
1:65536;2:0;4:6291456;6:262144|15663105|5:1:0:220|m,a,s,p Match?Exact match in Thumbprint's published controlled catalog captures: chromium 133.0.6943.16, chrome 156.0.8078.48, chrome 150.0.7871.128, +3 more.The fingerprint page shows the full measured match list. More on the catalog.268
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, +57 more.The fingerprint page shows the full measured match list. More on the catalog.263
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.59
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 26.6.2, safari 26.5, +2 more.The fingerprint page shows the full measured match list. More on the catalog.11
1:65536;2:0;4:6291456;6:262144|15663105|7:1:0:220|m,a,s,p5
1:65536;2:0;4:6291456;6:262144|15663105|7:1:0:256|m,a,s,p5
1:65536;2:0;4:6291456;6:262144|15663105|11:1:0:220|m,a,s,p3
1:65536;2:0;4:6291456;6:262144|15663105|13:1:0:220|m,a,s,p3

TCP SYN (p0f)

fingerprintco-occurrences
6:54+10:0:1220:65535,9:mss,sok,ts,nop,ws:flow:0366
6:51+13:0:1220:65535,9:mss,sok,ts,nop,ws:flow:0222
6:52+12:0:1220:65535,9:mss,sok,ts,nop,ws:flow:0164
6:57+7:0:1220:65535,9:mss,sok,ts,nop,ws:flow:0145
6:56+8:0:1220:65535,9:mss,sok,ts,nop,ws:flow:0136
6:60+4:0:1220:65535,9:mss,sok,ts,nop,ws:flow:0117
6:61+3:0:1220:65535,9:mss,sok,ts,nop,ws:flow:0117
6:58+6:0:1220:65535,9:mss,sok,ts,nop,ws:flow:078
6:55+9:0:1220:65535,9:mss,sok,ts,nop,ws:flow:059
6:49+15:0:1220:65535,9:mss,sok,ts,nop,ws:flow:040

User-Agent

fingerprintco-occurrences
Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/154.0.0.0 Safari/537.36609
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/155.0.0.0 Safari/537.36578
Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/155.0.0.0 Safari/537.36172
Mozilla/5.051
Mozilla/5.0 (Macintosh) Chrome/130 Safari/537.3611
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 Chrome/124 Safari/537.366
Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 Chrome/124 Safari/537.365
Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/124.0 Safari/537.364
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

Country

fingerprintco-occurrences
US · United States1470
IT · Italy5
DE · Germany3
NP · Nepal3
RU · Russia2
AU · Australia1
SE · Sweden1
FI · Finland1

Network (ASN)

fingerprintco-occurrences
AS54113 · Fastly, Inc.955
AS394192 · Fastly, Inc.516
AS12874 · Fastweb SpA4
AS38565 · Ncell Pvt. Ltd.3
AS43357 · Owl Limited2
AS12389 · PJSC Rostelecom2
AS50304 · Blix Solutions AS1
AS39351 · 31173 Services AB1
AS136557 · Host Universal Pty Ltd1
AS8434 · Telenor Sverige AB1

TLS supported groups

fingerprintco-occurrences
0a0a,11ec,001d,0017,0018 Match?Exact match in Thumbprint's published controlled catalog captures: chrome 155.0.8059.40, chrome 156.0.8078.73, chromium 156.0.8078.47, +8 more.The fingerprint page shows the full measured match list. More on the catalog.1102
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.92

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