TCP SYN (p0f)

4:78+?:0:1380:65535,8:mss,sok,ts,nop,ws:df,id+:0

first seen 2026-07-28 13:51 · last seen 2026-10-26 03:01 · 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

IP version4
Initial TTL78+?
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_5ac7197df9d217

HTTP request (JA4H)

fingerprintco-occurrences
ge20nn030000_80b089f68b8e_000000000000_00000000000012
ge20nn020000_e5a56608905c_000000000000_0000000000004
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,a17

TCP SYN (JA4T)

fingerprintco-occurrences
65535_2-4-8-1-3_1380_817

User-Agent

fingerprintco-occurrences
facebookexternalhit/1.1 (+http://www.facebook.com/externalhit_uatext.php)12
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

Country

fingerprintco-occurrences
DE · Germany12
US · United States5

Network (ASN)

fingerprintco-occurrences
AS32934 · Facebook, Inc.17

TLS supported groups

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