TCP SYN (p0f)

4:51+13:0:1460:mss*22,7:mss,sok,ts,nop,ws:df,id+:0

first seen 2026-06-22 20:04 · last seen 2026-10-23 22:45 · 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
MSS1460
Window sizemss*22
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
t12d330600_5172cef6ed69_021165082e1c4
t13d131100_f57a46bbacb6_e5728521abd43
t13d131000_f57a46bbacb6_e7c285222651 Match?Exact match in Thumbprint's published controlled catalog captures: go-net/http 1.23.12.The fingerprint page shows the full measured match list. More on the catalog.2
t13i170900_5b57614c22b0_78e6aca7449b2
t12d130600_2d7513195f68_021165082e1c1
t13d3013h2_1d37bd780c83_8537cf56674e Match?Exact match in Thumbprint's published controlled catalog captures: curl 8.18.0.The fingerprint page shows the full measured match list. More on the catalog.1

HTTP request (JA4H)

fingerprintco-occurrences
ge11nr040000_88d30a62b7ad_000000000000_0000000000005
ge11nn10zhcn_9c0cf7475f83_000000000000_0000000000002
ge11nr040000_8391bea91fb6_000000000000_0000000000002
ge11nr10zhcn_9c0cf7475f83_000000000000_0000000000001
ge20nn030000_bf75ddd0bb29_000000000000_0000000000001
ge11nn070000_07b5c846fda8_000000000000_0000000000001
ge11nn050000_0c34b9a6def6_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.1

TCP SYN (JA4T)

fingerprintco-occurrences
32120_2-4-8-1-3_1460_78

User-Agent

fingerprintco-occurrences
Mozilla/5.0 AppleWebKit/537.36 (KHTML, like Gecko) Chrome/123.0.6312.86 Safari/537.365
Mozilla/5.0 (iPhone; CPU iPhone OS 13_2_3 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/13.0.3 Mobile/15E148 Safari/604.13
Go-http-client/1.12
libredtail-http2
curl/8.14.11

Country

fingerprintco-occurrences
US · United States8
NL · Netherlands2
VN · Vietnam2
FR · France1

Network (ASN)

fingerprintco-occurrences
AS21859 · Zenlayer Inc5
AS45102 · Alibaba (US) Technology Co., Ltd.3
AS150862 · VPSTTT COMPUTER COMPANY LIMITED2
AS51167 · Contabo GmbH1
AS211486 · Alferov Aleksey Aleksandrovich1
AS210328 · AO ALMAZ1

TLS supported groups

fingerprintco-occurrences
11ec,001d,0017,001e,0018,0019,0100,0101 Match?Exact match in Thumbprint's published controlled catalog captures: python-httpx 0.28.1, python-requests 2.34.2, curl 8.23.0, +4 more.The fingerprint page shows the full measured match list. More on the catalog.1