TCP SYN (p0f)

4:51+13:0:1200:mss*44,7:mss,sok,ts,nop,ws:df,id+:0

first seen 2026-06-28 02:25 · last seen 2026-10-23 22:26 · JSON

Distinct clients per day (last 30 days, peak 3/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 TTL51+13
Options length0
MSS1200
Window sizemss*44
Window scale7
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
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
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.2
t13d1517h2_8daaf6152771_b1ff8ab2d16f1

HTTP request (JA4H)

fingerprintco-occurrences
ge20nn030000_bf75ddd0bb29_000000000000_0000000000003
ge20nr10ruru_20ac21c1ffbc_000000000000_0000000000001
ge20nr08ruru_48f5c0c9641d_000000000000_0000000000001
ge20nr11enus_351166502e22_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;4:6291456;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.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, +60 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_1200_75

User-Agent

fingerprintco-occurrences
curl/8.14.13
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/148.0.0.0 Safari/537.361
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/154.0.0.0 Safari/537.361
Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/534.24 (KHTML, like Gecko) Chrome/123.0.6312.118 Safari/534.24 XiaoMi/MiuiBrowser/14.47.1-gn1

Country

fingerprintco-occurrences
US · United States4
RU · Russia2

Network (ASN)

fingerprintco-occurrences
AS12389 · PJSC Rostelecom2
AS14618 · Amazon.com, Inc.1
AS263740 · Corporacion Laceibanetsociety1
AS52485 · networksdelmanana.com1
AS263179 · Webline Services, 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: 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.3

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_5a1f323ef56d2