User-Agent

curl/8.21.0

first seen 2026-07-01 22:56 · last seen 2026-09-12 17:42 · JSON

Last 7 days (57 observations)

Distinct clients per day (last 30 days, peak 205/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 / clientcurl 8.21.0
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
t13d2013h1_2b729b4bf6f3_e24568c0d440546
t13d3013h2_1d37bd780c83_8537cf56674e29
t13d3012h2_1d37bd780c83_882d495ac381 Match?Exact match in Thumbprint's published controlled catalog captures: curl 8.21.0, curl 8.22.0, curl 8.20.0, +6 more.The fingerprint page shows the full measured match list. More on the catalog.3
t12d2109h1_76e208dd3e22_7af1ed941c262

HTTP request (JA4H)

fingerprintco-occurrences
ge11nn030000_fe444ad14866_000000000000_000000000000 Match?Exact match in Thumbprint's published controlled catalog captures: curl 8.16.0.The fingerprint page shows the full measured match list. More on the catalog.547
ge20nn020000_5594a17e7e7e_000000000000_000000000000 Match?Exact match in Thumbprint's published controlled catalog captures: curl 8.7.1, curl 8.5.0, curl 8.18.0, +9 more.The fingerprint page shows the full measured match list. More on the catalog.32
he11nn030000_fe444ad14866_000000000000_0000000000001

HTTP/2 frames (Akamai)

fingerprintco-occurrences
3:100;4:65536;2:0|1048510465|0|m,s,a,p Match?Exact match in Thumbprint's published controlled catalog captures: curl 8.13.0, curl 8.18.0, curl 8.21.0, +7 more.The fingerprint page shows the full measured match list. More on the catalog.32

TCP SYN (p0f)

fingerprintco-occurrences
4:50+14:0:1460:65535,6:mss,sok,ts,nop,ws:df,id+:050
4:51+13:0:1460:65535,6:mss,sok,ts,nop,ws:df,id+:038
4:49+15:0:1460:65535,6:mss,sok,ts,nop,ws:df,id+:028
4:52+12:0:1460:65535,6:mss,sok,ts,nop,ws:df,id+:018
4:50+14:0:1460:65535,4:mss,sok,ts,nop,ws:df,id+:015
4:51+13:0:1460:65535,4:mss,sok,ts,nop,ws:df,id+:014
4:49+15:0:1460:65535,8:mss,sok,ts,nop,ws:df,id+:014
4:48+16:0:1460:65535,6:mss,sok,ts,nop,ws:df,id+:013
4:50+14:0:1460:mss*44,7:mss,sok,ts,nop,ws:df,id+:012
4:52+12:0:1460:65535,4:mss,sok,ts,nop,ws:df,id+:012

TCP SYN (JA4T)

fingerprintco-occurrences
65535_2-4-8-1-3_1460_6192
65535_2-4-8-1-3_1460_469
65535_2-4-8-1-3_1460_858
64240_2-4-8-1-3_1460_753
65535_2-4-8-1-3_1460_246
64800_2-4-8-1-3_1440_712
65535_2-4-8-1-3_1440_612
64240_2-4-8-1-3_1412_107
65535_2-4-8-1-3_1368_66
65535_2-4-8-1-3_1452_66

Country

fingerprintco-occurrences
US · United States525
PK · Pakistan11
TR · Turkey7
AE · United Arab Emirates6
NL · Netherlands5
CZ · Czechia5
SE · Sweden4
DE · Germany3
GB · United Kingdom3
TW · Taiwan3

Network (ASN)

fingerprintco-occurrences
AS7922 · Comcast Cable Communications, LLC185
AS7018 · AT&T Enterprises, LLC42
AS20115 · Charter Communications LLC28
AS701 · Verizon Business27
AS22773 · Cox Communications Inc.22
AS6167 · Verizon Business17
AS21928 · T-Mobile USA, Inc.13
AS209 · CenturyLink Communications, LLC12
AS9541 · Cyber Internet Services (Pvt) Ltd.11
AS11427 · Charter Communications Inc8