TCP SYN (JA4T)

65280_2-4-8-1-3_1360_10

first seen 2026-07-27 07:22 · last seen 2026-10-06 18:33 · 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 window65280
Option kinds2-4-8-1-3
MSS1360
Window scale10

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
t13d3013h1_1d37bd780c83_8537cf56674e15
t13d3013h2_1d37bd780c83_8537cf56674e Match?Exact match in Thumbprint's published controlled catalog captures: curl 8.18.0.The fingerprint page shows the full measured match list. More on the catalog.3
t13d1617h2_86a278354501_3cbfd9057e0d Match?Exact match in Thumbprint's published controlled catalog captures: firefox 153.0, firefox 153.0.3, firefox 152.0.3, +10 more.The fingerprint page shows the full measured match list. More on the catalog.1
t13d1515h2_1f9c1ec88692_a54fffd0eb611

HTTP request (JA4H)

fingerprintco-occurrences
ge11nn040000_5d05004232a2_000000000000_00000000000015
ge20nn030000_dd5957970d8a_000000000000_0000000000003
ge20nr13enus_016d87568c43_000000000000_0000000000001
ge20nr11zhcn_3901d4197baf_000000000000_0000000000001

HTTP/2 frames (Akamai)

fingerprintco-occurrences
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.3
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.1
1:139264;2:0;4:121760;5:16384|12517377|3:0:0:42|m,p,a,s1

TCP SYN (p0f)

fingerprintco-occurrences
6:44+20:0:1360:mss*48,10:mss,sok,ts,nop,ws:flow:010
6:45+19:0:1360:mss*48,10:mss,sok,ts,nop,ws:flow:08
4:57+7:0:1360:mss*48,10:mss,sok,ts,nop,ws:df,id+:01
4:50+14:0:1360:mss*48,10:mss,sok,ts,nop,ws:df,id+:01

User-Agent

fingerprintco-occurrences
curl/8.22.018
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/145.0.0.0 Safari/537.361
Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:153.0) Gecko/20100101 Firefox/153.01

Country

fingerprintco-occurrences
PL · Poland18
US · United States1
CA · Canada1

Network (ASN)

fingerprintco-occurrences
AS16276 · OVH SAS18
AS5645 · TekSavvy Solutions, Inc.1
AS35916 · MULTACOM CORPORATION1