TCP SYN (p0f)

6:55+9:0:1440:65535,6:mss,nop,ws,nop,nop,ts,sok,eol+1:ecn,flow:0

first seen 2026-07-01 22:13 · last seen 2026-10-08 13:46 · 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 version6
Initial TTL55+9
Options length0
MSS1440
Window size65535
Window scale6
Options layoutmss,nop,ws,nop,nop,ts,sok,eol+1
Quirksecn,flow
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
t13d1517h2_8daaf6152771_3cbfd9057e0d Match?Exact match in Thumbprint's published controlled catalog captures: firefox 155.0.1, firefox 154.0, firefox 156.0, +7 more.The fingerprint page shows the full measured match list. More on the catalog.11
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.5
t13d1516h2_8daaf6152771_0c27189014cf Match?Exact match in Thumbprint's published controlled catalog captures: firefox 154.0, firefox 155.0.1, firefox 155.0, +4 more.The fingerprint page shows the full measured match list. More on the catalog.1
t13d1313h2_f57a46bbacb6_7f0f34a4126d1

HTTP request (JA4H)

fingerprintco-occurrences
ge20nr11enca_1d88e8a431b9_000000000000_0000000000009
ge20nn020000_e5a56608905c_000000000000_0000000000005
ge20nn12enca_7e62679e718a_000000000000_0000000000003
ge20nn08frfr_6452f234bcf7_000000000000_0000000000001

HTTP/2 frames (Akamai)

fingerprintco-occurrences
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.5
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.5
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.3
1:65536;2:0;4:131072;5:16384|12517377|5:0:0:22|m,p,a,s Match?Exact match in Thumbprint's published controlled catalog captures: firefox 153.0.3, firefox 154.0, firefox 153.0, +12 more.The fingerprint page shows the full measured match list. More on the catalog.2
1:65536;2:0;4:131072;5:16384|12517377|7:0:0:22|m,p,a,s Match?Exact match in Thumbprint's published controlled catalog captures: firefox 153.0.3, firefox 155.0, firefox 154.0, +3 more.The fingerprint page shows the full measured match list. More on the catalog.2
2:0;4:2097152;3:100;9:1|10485760|0|m,s,p,a1

TCP SYN (JA4T)

fingerprintco-occurrences
65535_2-1-3-1-1-8-4-0-0_1440_618

User-Agent

fingerprintco-occurrences
Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:156.0) Gecko/20100101 Firefox/156.07
Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/146.0.0.0 Safari/537.365
Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:157.0) Gecko/20100101 Firefox/157.05
Mozilla/5.0 (compatible; RedditApp/1.0)1

Country

fingerprintco-occurrences
CA · Canada12
US · United States5
FR · France1

Network (ASN)

fingerprintco-occurrences
AS5769 · Videotron Ltee12
AS14593 · Space Exploration Technologies Corporation5
AS3215 · Orange S.A.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
q13d0315h3_55b375c5d22e_bb76f32061e31