TCP SYN (JA4T)

21900_2-4-8-1-3_1460_10

first seen 2026-07-15 10:07 · last seen 2026-10-30 01:33 · JSON

Last 7 days (1 observations)

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 window21900
Option kinds2-4-8-1-3
MSS1460
Window scale10

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
t13d190900_9dc949149365_97f8aa674fd910
t13d4312h1_c7886603b240_b26ce05bbdd61

HTTP request (JA4H)

fingerprintco-occurrences
ge11nn040000_e1d2031bdfea_000000000000_00000000000010
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

TCP SYN (p0f)

fingerprintco-occurrences
4:52+12:0:1460:mss*15,10:mss,sok,ts,nop,ws:df,id+:05
4:56+8:0:1460:mss*15,10:mss,sok,ts,nop,ws:df,id+:03
4:55+9:0:1460:mss*15,10:mss,sok,ts,nop,ws:df,id+:02
4:51+13:0:1460:mss*15,10:mss,sok,ts,nop,ws:df,id+:01

User-Agent

fingerprintco-occurrences
Mozilla/5.0 (compatible; CensysInspect/1.1; +https://about.censys.io/)10
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/110.0.0.0 Safari/537.361

Country

fingerprintco-occurrences
US · United States7
DE · Germany3
NL · Netherlands1

Network (ASN)

fingerprintco-occurrences
AS398324 · Censys, Inc.7
AS398705 · Censys, Inc.3
AS199514 · Lancet Cloud1

TLS supported groups

fingerprintco-occurrences
11ec,11ed,11eb,0202,001d,0017,0018,00192
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