TCP SYN (p0f)

4:45+19:0:1460:65535,6:mss,nop,ws,nop,nop,ts,sok,eol+1:df,ecn:0

first seen 2026-06-18 08:41 · last seen 2026-08-31 15:59 · 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

IP version4
Initial TTL45+19
Options length0
MSS1460
Window size65535
Window scale6
Options layoutmss,nop,ws,nop,nop,ts,sok,eol+1
Quirksdf,ecn
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
t13d2013h2_a09f3c656075_7f0f34a4126d Match?Exact match in Thumbprint's published controlled catalog captures: safari 26.5.2, safari 26.4, safari 26.6.2, +2 more.The fingerprint page shows the full measured match list. More on the catalog.6
t13d4907h2_0d8feac7bc37_7395dae3b2f3 Match?Exact match in Thumbprint's published controlled catalog captures: curl 8.7.1.The fingerprint page shows the full measured match list. More on the catalog.2
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.2
t13d1517h2_8daaf6152771_dcad5a0539912
t13d3112h1_e8f1e7e78f70_b26ce05bbdd6 Match?Exact match in Thumbprint's published controlled catalog captures: php-guzzle 8.1.0, php-guzzle 8.0.2, php-guzzle 7.14.2, +6 more.The fingerprint page shows the full measured match list. More on the catalog.1

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.2
ge20nn05enus_3f99bc624e90_000000000000_000000000000 Match?Exact match in Thumbprint's published controlled catalog captures: urlsession 6.3.2, urlsession 6.3.3.The fingerprint page shows the full measured match list. More on the catalog.2
ge20nr13en00_54728652be35_000000000000_0000000000001
ge20nn05itit_3f99bc624e90_000000000000_0000000000001
ge20nn05engb_3f99bc624e90_000000000000_0000000000001
ge20nr13enus_5907f7c6644a_000000000000_0000000000001
ge20nr12engb_f8a3a1e39dc3_000000000000_0000000000001
ge20nn13engb_e66716e13e58_000000000000_0000000000001
ge20nr09enus_5ad46a65401a_000000000000_000000000000 Match?Exact match in Thumbprint's published controlled catalog captures: safari 26.5.2, safari 26.4, safari 26.6.2, +2 more.The fingerprint page shows the full measured match list. More on the catalog.1
ge20nn08enus_b65a39d4559c_000000000000_0000000000001

HTTP/2 frames (Akamai)

fingerprintco-occurrences
2:0;4:2097152;3:100;9:1|10485760|0|m,s,p,a4
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.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|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.2
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 26.5, safari 26.4, +2 more.The fingerprint page shows the full measured match list. More on the catalog.2

TCP SYN (JA4T)

fingerprintco-occurrences
65535_2-1-3-1-1-8-4-0-0_1460_610

User-Agent

fingerprintco-occurrences
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/149.0.0.0 Safari/537.364
HackerNews/1566 CFNetwork/3860.600.12 Darwin/25.5.03
curl/8.7.12
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/26.6.2 Safari/605.1.152
feeeed/37 CFNetwork/3860.300.31 Darwin/25.2.01
curl/8.5.01

Country

fingerprintco-occurrences
US · United States6
HR · Croatia3
LV · Latvia2
IT · Italy1
IL · Israel1

Network (ASN)

fingerprintco-occurrences
AS44306 · OMONIA d.o.o.3
AS12578 · SIA Tet2
AS33363 · Charter Communications, Inc2
AS12874 · Fastweb SpA1
AS10796 · Charter Communications Inc1
AS11427 · Charter Communications Inc1
AS8551 · Bezeq International Ltd.1
AS11404 · Wave Broadband1
AS11351 · Charter Communications Inc1

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_653d80c3fe9d2
q13d0311h3_55b375c5d22e_f2a83c8e78ae1