TCP SYN (JA4T)

65535_2-1-3-1-1-8-4-0-0_1250_6

first seen 2026-07-01 16:16 · last seen 2026-08-31 08:22 · 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 kinds2-1-3-1-1-8-4-0-0
MSS1250
Window scale6

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
t13d1516h2_8daaf6152771_806a8c22fdea Match?Exact match in Thumbprint's published controlled catalog captures: chrome 150.0.7871.187, chrome 151.0.7922.137, chromium 151.0.7922.34, +24 more.The fingerprint page shows the full measured match list. More on the catalog.7
t13d210900_6b2954d954da_00596cb448ee5
t13d171000_5b57614c22b0_78e6aca7449b3
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.2
t13d1515h2_8daaf6152771_a54fffd0eb611
t13d5911h1_a33745022dd6_1f22a2ca17c4 Match?Exact match in Thumbprint's published controlled catalog captures: node-fetch 23.11.1.The fingerprint page shows the full measured match list. More on the catalog.1
t13d4907h2_0d8feac7bc37_7395dae3b2f3 Match?Exact match in Thumbprint's published controlled catalog captures: curl 8.7.1.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 151.0.7922.137, edge 151.0.4129.93, +36 more.The fingerprint page shows the full measured match list. More on the catalog.4
ge11nr11engb_d21348767826_000000000000_0000000000002
ge11nr13kokr_695efbec79f4_000000000000_0000000000002
ge20nr09enus_5ad46a65401a_000000000000_000000000000 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.2
ge20nn14enus_d9ad99aff99a_000000000000_0000000000001
ge11nn10*000_6c8baa375ef4_000000000000_0000000000001
ge20nr11enus_187a9385d229_000000000000_0000000000001
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.1
ge20nr13enus_5907f7c6644a_000000000000_0000000000001
ge11nn10engb_aa59d875b51d_000000000000_0000000000001

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 149.0.7827.102, +59 more.The fingerprint page shows the full measured match list. More on the catalog.4
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.2
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
1:65536;2:0;4:131072;5:16384|12517377|3:0:0:22|m,p,a,s Match?Exact match in Thumbprint's published controlled catalog captures: firefox 153.0, firefox 153.0.3, firefox 154.0, +25 more.The fingerprint page shows the full measured match list. More on the catalog.1
3:100;4:10485760;2:0|1048510465|0|m,s,a,p Match?Exact match in Thumbprint's published controlled catalog captures: curl 8.7.1, curl 8.5.0.The fingerprint page shows the full measured match list. More on the catalog.1
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, +21 more.The fingerprint page shows the full measured match list. More on the catalog.1

TCP SYN (p0f)

fingerprintco-occurrences
6:50+14:0:1250:65535,6:mss,nop,ws,nop,nop,ts,sok,eol+1:ecn,flow:06
4:44+20:0:1250:65535,6:mss,nop,ws,nop,nop,ts,sok,eol+1:df,ecn:05
4:45+19:0:1250:65535,6:mss,nop,ws,nop,nop,ts,sok,eol+1:df,ecn:03
6:53+11:0:1250:65535,6:mss,nop,ws,nop,nop,ts,sok,eol+1:ecn,flow:02
4:41+23:0:1250:65535,6:mss,nop,ws,nop,nop,ts,sok,eol+1:df,ecn:01
4:51+13:0:1250:65535,6:mss,nop,ws,nop,nop,ts,sok,eol+1:df,ecn:01
4:53+11:0:1250:65535,6:mss,nop,ws,nop,nop,ts,sok,eol+1:df,ecn:01
4:41+23:0:1250:65535,6:mss,nop,ws,nop,nop,ts,sok,eol+1:df:01

User-Agent

fingerprintco-occurrences
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/150.0.0.0 Safari/537.367
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/151.0.0.0 Safari/537.365
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/26.5.2 Safari/605.1.153
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/26.4 Safari/605.1.152
curl/8.7.11
Mozilla/5.0 (compatible; Growero/1.0; +https://growero.io)1
Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:154.0) Gecko/20100101 Firefox/154.01

Country

fingerprintco-occurrences
US · United States8
KR · South Korea5
RO · Romania3
IN · India2
EE · Estonia1
AT · Austria1

Network (ASN)

fingerprintco-occurrences
AS714 · Apple Inc.8
AS3786 · LG DACOM Corporation5
AS42424 · ICS Endava SRL3
AS24560 · Bharti Airtel Ltd., Telemedia Services2
AS47736 · IT and Development Center of Ministry of Interior, Estonia1
AS60368 · Greentube GmbH1

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
q13d0311h3_55b375c5d22e_653d80c3fe9d5
q13d0311h3_55b375c5d22e_f2a83c8e78ae2
q13d0315h3_55b375c5d22e_dc5437974b471