TCP SYN (p0f)

4:55+9:0:1460:mss*44,8:mss,sok,ts,nop,ws:df,id+:0

first seen 2026-07-19 16:25 · last seen 2026-09-08 17:30 · JSON

Distinct clients per day (last 30 days, peak 2/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 TTL55+9
Options length0
MSS1460
Window sizemss*44
Window scale8
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_806a8c22fdea Match?Exact match in Thumbprint's published controlled catalog captures: chrome 150.0.7871.187, chrome 151.0.7922.137, chromium 151.0.7922.34, +24 more.The fingerprint page shows the full measured match list. More on the catalog.8
t13d4913h2_bd868743f55c_aac3338551363
t13d1515h1_8daaf6152771_de4a06bb82e33
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.2
t13d4412h1_fd39b124ee10_58ed7828516f1
t13d1517h2_8daaf6152771_dcad5a0539911
t13d1110h2_74323e352b6d_5603904660151

HTTP request (JA4H)

fingerprintco-occurrences
ge20nr12engb_54b4638ab28b_000000000000_0000000000005
ge20nr13engb_0c2c1d640f3e_000000000000_0000000000003
ge11nn13enus_9db22d02e17a_000000000000_0000000000003
ge20nr11enus_187a9385d229_000000000000_0000000000002
ge20nr14engb_00c893c2b404_000000000000_0000000000002
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.1
ge20nn13engb_0c2c1d640f3e_000000000000_0000000000001
ge20nn14engb_00c893c2b404_000000000000_0000000000001
ge20nn04enus_989c7cc05c9b_000000000000_0000000000001

HTTP/2 frames (Akamai)

fingerprintco-occurrences
3:1000;2:0;4:6291456;1:4096|15663105|0|s,m,p,a3
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, +43 more.The fingerprint page shows the full measured match list. More on the catalog.3
1:65536;2:0;4:131072;5:16384|12517377|3:0:0:22|m,p,a,s Match?Exact match in Thumbprint's published controlled catalog captures: firefox 153.0, firefox 153.0.3, firefox 154.0, +25 more.The fingerprint page shows the full measured match list. More on the catalog.2
1:65536;2:0;4:6291456;6:262144|15663105|1:1:0:220|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 149.0.7827.102, +59 more.The fingerprint page shows the full measured match list. More on the catalog.2
1:65536;2:0;4:6291456;6:262144|15663105|3:1:0:256|m,a,s,p1
1:65536;2:0;4:6291456;6:262144|15663105|7:1:0:256|m,a,s,p1
1:65536;2:0;4:6291456;6:262144|15663105|5:1:0:256|m,a,s,p1
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, +21 more.The fingerprint page shows the full measured match list. More on the catalog.1
1:65536;2:0;4:6291456;6:262144;4:1048576|15663105|1:0:0:256|m,a,s,p1

TCP SYN (JA4T)

fingerprintco-occurrences
64240_2-4-8-1-3_1460_819

User-Agent

fingerprintco-occurrences
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/150.0.0.0 Safari/537.3612
Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:152.0) Gecko/20100101 Firefox/152.02
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/107.0.0.0 Safari/537.362
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/101.0.4951.67 Safari/537.361
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/68.0.3409.631 Safari/537.361
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/135.0.0.9 Safari/537.36 Edg/135.0.0.91

Country

fingerprintco-occurrences
SG · Singapore14
US · United States2
CA · Canada2
NL · Netherlands1

Network (ASN)

fingerprintco-occurrences
AS9009 · M247 Europe SRL16
AS210558 · 1337 Services GmbH1
AS212238 · Datacamp Limited1
AS199218 · Proton AG1

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_653d80c3fe9d3
q13d0315h3_55b375c5d22e_dc5437974b472