TCP SYN (JA4T)

28288_2-4-8-1-3_1420_7

first seen 2026-09-16 07:22 · last seen 2026-10-15 12:05 · 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

TCP window28288
Option kinds2-4-8-1-3
MSS1420
Window scale7

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
t13d1713h1_ab0a1bf427ad_ecd0401ec68b Match?Exact match in Thumbprint's published controlled catalog captures: python-httpx 0.28.1.The fingerprint page shows the full measured match list. More on the catalog.8

HTTP request (JA4H)

fingerprintco-occurrences
ge11nn050000_be0d0b335e46_000000000000_0000000000008

TCP SYN (p0f)

fingerprintco-occurrences
4:58+6:0:1420:28288,7:mss,sok,ts,nop,ws:df:08

User-Agent

fingerprintco-occurrences
Mozilla/5.0 AppleWebKit/537.36 (KHTML, like Gecko; compatible; Claude-User/1.0; +claude-user@anthropic.com)8

Country

fingerprintco-occurrences
US · United States8

Network (ASN)

fingerprintco-occurrences
AS396982 · Google LLC8

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