TCP SYN (p0f)

4:51+13:0:1260:mss*52,7:mss,sok,ts,nop,ws:df,id+:0

first seen 2026-09-25 23:22 · last seen 2026-10-23 22:36 · 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 TTL51+13
Options length0
MSS1260
Window sizemss*52
Window scale7
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
t13d3013h2_1d37bd780c83_8537cf56674e6

HTTP request (JA4H)

fingerprintco-occurrences
ge20nn030000_ff50983941c1_000000000000_0000000000003
ge20nn020000_5594a17e7e7e_000000000000_000000000000 Match?Exact match in Thumbprint's published controlled catalog captures: curl 8.7.1, curl 8.5.0, curl 8.13.0, +11 more.The fingerprint page shows the full measured match list. More on the catalog.2
ge20nn030000_bf75ddd0bb29_000000000000_0000000000001

HTTP/2 frames (Akamai)

fingerprintco-occurrences
3:100;4:65536;2:0|1048510465|0|m,s,a,p Match?Exact match in Thumbprint's published controlled catalog captures: curl 8.13.0, curl 8.18.0, curl 8.21.0, +8 more.The fingerprint page shows the full measured match list. More on the catalog.6

TCP SYN (JA4T)

fingerprintco-occurrences
65520_2-4-8-1-3_1260_76

User-Agent

fingerprintco-occurrences
curl/8.14.15
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/140.0.0.0 Safari/537.361

Country

fingerprintco-occurrences
NL · Netherlands5
US · United States1

Network (ASN)

fingerprintco-occurrences
AS39351 · 31173 Services AB5
AS265645 · HOSTINGFOREX S.A.1

TLS supported groups

fingerprintco-occurrences
11ec,001d,0017,001e,0018,0019,0100,0101 Match?Exact match in Thumbprint's published controlled catalog captures: node-fetch 24.22.1, python-httpx 0.28.1, python-requests 2.34.2, +2 more.The fingerprint page shows the full measured match list. More on the catalog.1