TCP SYN (p0f)

6:49+15:0:1440:65535,7:mss,nop,nop,sok,nop,ws:flow:0

first seen 2026-07-16 14:19 · last seen 2026-10-23 22:44 · JSON

Distinct clients per day (last 30 days, peak 11/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 version6
Initial TTL49+15
Options length0
MSS1440
Window size65535
Window scale7
Options layoutmss,nop,nop,sok,nop,ws
Quirksflow
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
t13d3013h2_1d37bd780c83_8537cf56674e20
t13d1516h2_8daaf6152771_d8a2da3f94cd Match?Exact match in Thumbprint's published controlled catalog captures: chromium 149.0.7827.102, chrome 149.0.7827.102, chrome 149.0.7827.156, +25 more.The fingerprint page shows the full measured match list. More on the catalog.9

HTTP request (JA4H)

fingerprintco-occurrences
ge20nn030000_bf75ddd0bb29_000000000000_00000000000020
ge20nn13zhcn_0c2c1d640f3e_000000000000_0000000000005
ge20nr12zhcn_54b4638ab28b_000000000000_0000000000002
ge20nn13zhcn_9519c2577190_000000000000_0000000000002

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, +8 more.The fingerprint page shows the full measured match list. More on the catalog.20
1:65536;2:0;4:6291456;6:262144|15663105|1:1:0:256|m,a,s,p Match?Exact match in Thumbprint's published controlled catalog captures: chromium 131.0.6778.33, chromium 151.0.7922.34, chrome 151.0.7922.137, +57 more.The fingerprint page shows the full measured match list. More on the catalog.6
1:65536;2:0;4:6291456;6:262144|15663105|1:1:0:220|m,a,s,p Match?Exact match in Thumbprint's published controlled catalog captures: chrome 150.0.7871.187, chromium 149.0.7827.102, chrome 152.0.7977.83, +81 more.The fingerprint page shows the full measured match list. More on the catalog.2
1:65536;2:0;4:6291456;6:262144|15663105|3:1:0:256|m,a,s,p1

TCP SYN (JA4T)

fingerprintco-occurrences
65535_2-1-1-4-1-3_1440_729

User-Agent

fingerprintco-occurrences
curl/8.14.120
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/144.0.0.0 Safari/537.367
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/142.0.0.0 Safari/537.362

Country

fingerprintco-occurrences
CN · China9
NO · Norway4
NL · Netherlands3
SE · Sweden3
RO · Romania2
BG · Bulgaria2
GB · United Kingdom2
FR · France2
MX · Mexico1
CZ · Czechia1

Network (ASN)

fingerprintco-occurrences
AS9009 · M247 Europe SRL12
AS4837 · CHINA UNICOM China169 Backbone4
AS396356 · Latitude.sh3
AS212238 · Datacamp Limited2
AS60068 · Datacamp Limited2
AS63835 · CT HuNan Changsha IDC2
AS56040 · China Mobile communications corporation1
AS56045 · China Mobile communications corporation1
AS24400 · Shanghai Mobile Communications Co.,Ltd.1
AS209181 · Zenex 5ive Limited1

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.20

Cross-transport links

TLS ClientHello fingerprints observed from the same client via the beacon's correlation id on the other transport (e.g. this stack over TCP ↔ that stack over QUIC).

fingerprintlinked observations
q13d0311h3_55b375c5d22e_653d80c3fe9d2