TCP SYN (p0f)

6:42+22:0:1440:mss*45,7:mss,sok,ts,nop,ws:flow:0

first seen 2026-06-26 11:19 · last seen 2026-10-31 11:12 · JSON

Last 7 days (22 observations)

Distinct clients per day (last 30 days, peak 117/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

IP version6
Initial TTL42+22
Options length0
MSS1440
Window sizemss*45
Window scale7
Options layoutmss,sok,ts,nop,ws
Quirksflow
Payload class0

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
t13d301000_1d37bd780c83_3550537cd59b1699
t13d1516h2_8daaf6152771_02713d6af862 Match?Exact match in Thumbprint's published controlled catalog captures: chromium 131.0.6778.33, chromium 134.0.6998.35, chromium 133.0.6943.16.The fingerprint page shows the full measured match list. More on the catalog.144
t13d1517h2_8daaf6152771_b1ff8ab2d16f35
t13d521100_b262b3658495_8e6e362c5eac10
t13d3112h1_e8f1e7e78f70_b26ce05bbdd6 Match?Exact match in Thumbprint's published controlled catalog captures: php-guzzle 8.2.0, php-guzzle 8.1.0, php-guzzle 8.3.1, +12 more.The fingerprint page shows the full measured match list. More on the catalog.7
t13d131100_f57a46bbacb6_ab7e3b40a677 Match?Exact match in Thumbprint's published controlled catalog captures: go-net/http 1.26.6, go-net/http 1.26.5, go-net/http 1.26.4.The fingerprint page shows the full measured match list. More on the catalog.6
t12d290700_fc2078a0b8c0_8c06664c3ac53
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
t13d131000_f57a46bbacb6_e7c285222651 Match?Exact match in Thumbprint's published controlled catalog captures: go-net/http 1.23.12.The fingerprint page shows the full measured match list. More on the catalog.2
t13d181100_85036bcba153_d41ae481755e2

HTTP request (JA4H)

fingerprintco-occurrences
ge11nr08enus_002f1ef91713_000000000000_0000000000001691
ge20nr13enus_e2ac93ffb364_000000000000_000000000000178
ge11nn050000_2469c960a647_000000000000_0000000000008
ge11nr08enus_0b4981d9e830_000000000000_0000000000008
ge11nr030000_cd680697de12_000000000000_0000000000004
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.4
he11nn050000_b223a0ebb0b5_000000000000_0000000000003
ge20nn030000_bf75ddd0bb29_000000000000_0000000000003
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.2
ge11nn06en00_98e697c2fa06_000000000000_0000000000002

HTTP/2 frames (Akamai)

fingerprintco-occurrences
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, +60 more.The fingerprint page shows the full measured match list. More on the catalog.178
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;4:6291456;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, +85 more.The fingerprint page shows the full measured match list. More on the catalog.3
1:65536;2:0;4:131072;5:16384|12517377|1:0:0:42|m,p,a,s2
1:65536;2:0;3:1000;4:6291456;6:262144|15663105|1:1:0:256|m,a,s,p1
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, +3 more.The fingerprint page shows the full measured match list. More on the catalog.1
3:100;4:1073741824;2:0|1073676289|0|m,p,s,a1
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

TCP SYN (JA4T)

fingerprintco-occurrences
64800_2-4-8-1-3_1440_71920

User-Agent

fingerprintco-occurrences
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/124.0.0.0 Safari/537.361692
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/145.0.0.0 Safari/537.3626
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/145.0.0.0 Safari/537.3625
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/142.0.0.0 Safari/537.3625
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/143.0.0.0 Safari/537.3622
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/144.0.0.0 Safari/537.3622
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/144.0.0.0 Safari/537.3621
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/144.0.0.0 Safari/537.36 Edg/144.0.0.019
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/145.0.0.0 Safari/537.36 Edg/145.0.0.018
Mozilla/5.09

Country

fingerprintco-occurrences
FR · France1720
US · United States126
SG · Singapore53
IN · India8
DE · Germany5
FI · Finland4
SE · Sweden2
RO · Romania1
PL · Poland1
KZ · Kazakhstan1

Network (ASN)

fingerprintco-occurrences
AS51167 · Contabo GmbH1716
AS214483 · FiberPower LLC171
AS47583 · Hostinger International Limited8
AS16276 · OVH SAS7
AS62610 · Zenlayer Inc7
AS24940 · Hetzner Online GmbH6
AS215540 · GLOBAL CONNECTIVITY SOLUTIONS LLP2
AS197540 · netcup GmbH2
AS58061 · Scalaxy B.V.1
AS36183 · Akamai Technologies, Inc.1

TLS supported groups

fingerprintco-occurrences
0a0a,001d,0017,0018178
001d,0017,001e,0019,0018,0100,0101,0102,0103,0104 Match?Exact match in Thumbprint's published controlled catalog captures: curl 8.13.0, php-guzzle 8.3.1, curl 7.88.1, +10 more.The fingerprint page shows the full measured match list. More on the catalog.4
11ec,001d,0017,001e,0018,0019,0100,0101 Match?Exact match in Thumbprint's published controlled catalog captures: python-httpx 0.28.1, python-requests 2.34.2, curl 8.23.0, +4 more.The fingerprint page shows the full measured match list. More on the catalog.4

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_5a1f323ef56d1
q13d0312h3_55b375c5d22e_178839b6cec11