TCP SYN (p0f)

4:50+14:0:1412:mss*44,10:mss,sok,ts,nop,ws:df,id+:0

first seen 2026-07-02 20:33 · last seen 2026-10-21 20:18 · 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 TTL50+14
Options length0
MSS1412
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
t13d4312h1_c7886603b240_b26ce05bbdd61
t13d1616h2_86a278354501_0c27189014cf Match?Exact match in Thumbprint's published controlled catalog captures: firefox 153.0, firefox 153.0.3, firefox 152.0.6, +10 more.The fingerprint page shows the full measured match list. More on the catalog.1

HTTP request (JA4H)

fingerprintco-occurrences
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
ge20nr10pl00_b3034183f430_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, +32 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_1412_102

User-Agent

fingerprintco-occurrences
Mozilla/5.0 (X11; Linux x86_64; rv:150.0) Gecko/20100101 Firefox/150.01
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/119.0.0.0 Safari/537.361

Country

fingerprintco-occurrences
PL · Poland1
IN · India1

Network (ASN)

fingerprintco-occurrences
AS31242 · P4 Sp. z o.o.1
AS133661 · Netplus Broadband Services Private Limited1

TLS supported groups

fingerprintco-occurrences
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.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_dc5437974b471