TCP SYN (JA4T)

43200_2-1-1-8-1-3_1440_9

first seen 2026-08-15 08:07 · last seen 2026-10-25 13:10 · JSON

Last 7 days (15 observations)

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 window43200
Option kinds2-1-1-8-1-3
MSS1440
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
t13d1715h2_5b57614c22b0_a54fffd0eb6136
t13d3013h2_1d37bd780c83_8537cf56674e1

HTTP request (JA4H)

fingerprintco-occurrences
ge20nn12enus_a72b71f519fc_000000000000_00000000000018
ge20nr12enus_a72b71f519fc_000000000000_00000000000011
ge20nr11enus_187a9385d229_000000000000_0000000000006
ge20nn030000_bf75ddd0bb29_000000000000_0000000000001
ge20nn11enus_684b26f0fcdf_000000000000_0000000000001

HTTP/2 frames (Akamai)

fingerprintco-occurrences
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 155.0.1, +31 more.The fingerprint page shows the full measured match list. More on the catalog.4
1:65536;2:0;4:131072;5:16384|12517377|3:0:0:42|m,p,a,s Match?Exact match in Thumbprint's published controlled catalog captures: firefox 154.0, firefox 152.0.5, firefox 152.0.1, +3 more.The fingerprint page shows the full measured match list. More on the catalog.3
1:65536;2:0;4:131072;5:16384|12517377|17:0:0:42|m,p,a,s2
1:65536;2:0;4:131072;5:16384|12517377|13:0:0:42|m,p,a,s2
1:65536;2:0;4:131072;5:16384|12517377|15:0:0:42|m,p,a,s2
1:65536;2:0;4:131072;5:16384|12517377|19:0:0:42|m,p,a,s2
1:65536;2:0;4:131072;5:16384|12517377|21:0:0:42|m,p,a,s2
1:65536;2:0;4:131072;5:16384|12517377|25:0:0:42|m,p,a,s2
1:65536;2:0;4:131072;5:16384|12517377|27:0:0:42|m,p,a,s2
1:65536;2:0;4:131072;5:16384|12517377|31:0:0:42|m,p,a,s2

TCP SYN (p0f)

fingerprintco-occurrences
6:50+14:0:1440:mss*30,9:mss,nop,nop,ts,nop,ws:flow:021
6:43+21:0:1440:mss*30,9:mss,nop,nop,ts,nop,ws:flow:015
6:52+12:0:1440:mss*30,9:mss,nop,nop,ts,nop,ws:flow:01

User-Agent

fingerprintco-occurrences
Mozilla/5.0 (X11; Linux x86_64; rv:140.0) Gecko/20100101 Firefox/140.021
Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:140.0) Gecko/20100101 Firefox/140.015
curl/8.14.11

Country

fingerprintco-occurrences
US · United States21
SE · Sweden15
CA · Canada1

Network (ASN)

fingerprintco-occurrences
AS11878 · tzulo, inc.21
AS212238 · Datacamp Limited16

TLS supported groups

fingerprintco-occurrences
11ec,001d,0017,0018,0019,0100,010115
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.1