TCP SYN (p0f)

4:84+?:0:1380:65535,8:mss,sok,ts,nop,ws:df,id+:0

first seen 2026-08-08 19:13 · last seen 2026-10-23 22:43 · 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 TTL84+?
Options length0
MSS1380
Window size65535
Window scale8
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
t13d3111h2_e8f1e7e78f70_5ac7197df9d223

HTTP request (JA4H)

fingerprintco-occurrences
ge20nn030000_80b089f68b8e_000000000000_00000000000017
ge20nn09enus_c5abe4666a67_000000000000_0000000000003
ge20nn070000_1903711a2262_000000000000_0000000000002
ge20nn030000_6dac75bd47eb_000000000000_000000000000 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.1

HTTP/2 frames (Akamai)

fingerprintco-occurrences
1:4096;2:0;5:16384;6:131072;3:100;4:65536|26148865|0|m,s,p,a21
1:4096;2:0;5:16384;6:131072;3:100;4:65536;11105:65535;11106:65535;11107:65535;11108:10;11109:10|26148865|0|m,s,p,a2

TCP SYN (JA4T)

fingerprintco-occurrences
65535_2-4-8-1-3_1380_823

User-Agent

fingerprintco-occurrences
facebookexternalhit/1.1 (+http://www.facebook.com/externalhit_uatext.php)13
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/145.0.0.0 Safari/537.36 (compatible; meta-externalagent/1.1 (+https://developers.facebook.com/docs/sharing/webmasters/crawler))5
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/145.0.0.0 Safari/537.36 (compatible; meta-externalagent/1.1 (+https://developers.facebook.com/docs/sharing/webmasters/crawler))4
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/145.0.0.0 Safari/537.36 Edg/145.0.0.0 (compatible; meta-externalagent/1.1 (+https://developers.facebook.com/docs/sharing/webmasters/crawler))1

Country

fingerprintco-occurrences
US · United States14
SG · Singapore9

Network (ASN)

fingerprintco-occurrences
AS32934 · Facebook, Inc.23

TLS supported groups

fingerprintco-occurrences
001d,0017,001e,0019,00181