TCP SYN (p0f)

4:44+20:0:1460:mss*44,10:mss,sok,ts,nop,ws:df,id+:0

first seen 2026-06-11 00:47 · last seen 2026-10-23 22:39 · JSON

Distinct clients per day (last 30 days, peak 8/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 version4
Initial TTL44+20
Options length0
MSS1460
Window sizemss*44
Window scale10
Options layoutmss,sok,ts,nop,ws
Quirksdf,id+
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
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.41
t13d4113h2_8ae0994cad11_86f67be995ff21
t13d3013h2_1d37bd780c83_8537cf56674e8
t13d1615h2_86a278354501_a54fffd0eb617
t13d4312h1_c7886603b240_b26ce05bbdd65
t13d1614h2_86a278354501_53a6d0ab1c424
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.3
t13d101000_61a7ad8aa9b6_3ea2f44fd1af2
t13d521100_b262b3658495_8e6e362c5eac1
t13d3013h1_1d37bd780c83_ecd0401ec68b1

HTTP request (JA4H)

fingerprintco-occurrences
ge20nn030000_042112399351_000000000000_000000000000 Match?Exact match in Thumbprint's published controlled catalog captures: curl 8.13.0.The fingerprint page shows the full measured match list. More on the catalog.21
ge20nr13engb_54728652be35_000000000000_00000000000020
ge20nn030000_bf75ddd0bb29_000000000000_0000000000008
ge20nr14engb_186438911b7e_000000000000_0000000000006
ge20nr13enus_47bedc02e943_000000000000_0000000000005
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.5
ge20nr12enus_a4e537ffe33a_000000000000_0000000000004
ge20nr15engb_cbb1aaa5e388_000000000000_0000000000004
ge11nr030000_cd680697de12_000000000000_0000000000003
ge20nr16engb_ce20326d9e21_000000000000_0000000000002

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.29
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.27
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.14
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.7
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;4:6291456;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.1

TCP SYN (JA4T)

fingerprintco-occurrences
64240_2-4-8-1-3_1460_1026

User-Agent

fingerprintco-occurrences
Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/149.0.0.0 Safari/537.3637
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/147.0.0.0 Safari/537.3621
Mozilla/5.0 (X11; Linux x86_64; rv:151.0) Gecko/20100101 Firefox/151.011
curl/8.14.18
Go-http-client/1.13
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/148.0.0.0 Safari/537.363
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/142.0.0.0 Safari/537.362
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/147.0.0.0 Safari/537.362
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/146.0.0.0 Safari/537.361
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.361

Country

fingerprintco-occurrences
AU · Australia70
GB · United Kingdom4
FR · France4
FI · Finland4
DE · Germany3
BR · Brazil2
RU · Russia2
TR · Turkey2
UA · Ukraine1
IT · Italy1

Network (ASN)

fingerprintco-occurrences
AS38195 · Superloop67
AS63949 · Akamai Connected Cloud8
AS24940 · Hetzner Online GmbH4
AS7545 · TPG Telecom Limited3
AS8641 · BACKBONE AS of Nauka-Svyaz2
AS219502 · Storm Industries LLC2
AS28126 · BRISANET SERVICOS DE TELECOMUNICACOES S.A2
AS16276 · OVH SAS1
AS51207 · Free Mobile SAS1
AS3215 · Orange S.A.1

TLS supported groups

fingerprintco-occurrences
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.8
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.5
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.1

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
q13d0312h3_55b375c5d22e_5a06198afb9324
q13d0315h3_55b375c5d22e_bb76f32061e34