TCP SYN (p0f)

4:112+16:0:1399:65535,8:mss,nop,ws,nop,nop,sok:df,id+,ecn:0

first seen 2026-10-18 20:47 · last seen 2026-10-18 20:47 · 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 TTL112+16
Options length0
MSS1399
Window size65535
Window scale8
Options layoutmss,nop,ws,nop,nop,sok
Quirksdf,id+,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
t13d1312h2_f57a46bbacb6_ab7e3b40a677 Match?Exact match in Thumbprint's published controlled catalog captures: go-net/http 1.26.6, go-net/http 1.26.10, go-net/http 1.26.9, +7 more.The fingerprint page shows the full measured match list. More on the catalog.1

HTTP request (JA4H)

fingerprintco-occurrences
ge20nr020000_fb4f949fd323_000000000000_0000000000001

HTTP/2 frames (Akamai)

fingerprintco-occurrences
2:0;4:4194304;5:16384;6:10485760|1073741824|0|a,m,p,s Match?Exact match in Thumbprint's published controlled catalog captures: go-net/http 1.26.6, go-net/http 1.26.10, go-net/http 1.26.9, +8 more.The fingerprint page shows the full measured match list. More on the catalog.1

TCP SYN (JA4T)

fingerprintco-occurrences
65535_2-1-3-1-1-4_1399_81

User-Agent

fingerprintco-occurrences
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/123.0.0.0 Safari/537.361

Country

fingerprintco-occurrences
DE · Germany1

Network (ASN)

fingerprintco-occurrences
AS62651 · Strong Technology, LLC.1

TLS supported groups

fingerprintco-occurrences
11ec,001d,0017,0018,0019 Match?Exact match in Thumbprint's published controlled catalog captures: firefox 158.0.1, firefox 157.0, firefox 157.0.1, +5 more.The fingerprint page shows the full measured match list. More on the catalog.1