User-Agent

cf-defaults-research/0.1 (academic research; fetches robots.txt and homepage once)

first seen 2026-10-18 11:17 · last seen 2026-10-18 11:39 · JSON

Distinct clients per day (last 30 days, peak 2/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

Browser / clientcf-defaults-research 0.1
Noteinferred from the self-declared string — a claim, not a measurement; compare with the wire fingerprints above

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
t13d171100_ab0a1bf427ad_8e6e362c5eac4

HTTP request (JA4H)

fingerprintco-occurrences
ge11nn050000_ea6f06182064_000000000000_0000000000004

TCP SYN (p0f)

fingerprintco-occurrences
6:47+17:0:1260:65535,6:mss,nop,ws,nop,nop,ts,sok,eol+1:ecn,flow:02
4:41+23:0:1250:65535,6:mss,nop,ws,nop,nop,ts,sok,eol+1:df:02

TCP SYN (JA4T)

fingerprintco-occurrences
65535_2-1-3-1-1-8-4-0-0_1250_62
65535_2-1-3-1-1-8-4-0-0_1260_62

Country

fingerprintco-occurrences
DE · Germany4

Network (ASN)

fingerprintco-occurrences
AS12816 · Leibniz-Rechenzentrum4

TLS supported groups

fingerprintco-occurrences
11ec,001d,0017,001e,0018,0019,0100,0101 Match?Exact match in Thumbprint's published controlled catalog captures: node-fetch 24.22.1, python-httpx 0.28.1, python-requests 2.34.2, +2 more.The fingerprint page shows the full measured match list. More on the catalog.4