TCP SYN (JA4T)

65280_2-4-8-1-3_1280_10

first seen 2026-07-20 10:51 · last seen 2026-10-23 15:24 · 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

TCP window65280
Option kinds2-4-8-1-3
MSS1280
Window scale10

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
t13d1312h2_f57a46bbacb6_f50d94e863eb Match?Exact match in Thumbprint's published controlled catalog captures: go-net/http 1.27.1, go-net/http 1.27.3, go-net/http 1.27.0, +1 more.The fingerprint page shows the full measured match list. More on the catalog.9
t13d1312h2_f57a46bbacb6_ab7e3b40a677 Match?Exact match in Thumbprint's published controlled catalog captures: go-net/http 1.26.6, go-net/http 1.26.10, go-net/http 1.26.9, +7 more.The fingerprint page shows the full measured match list. More on the catalog.8
t13d1516h2_8daaf6152771_0c27189014cf Match?Exact match in Thumbprint's published controlled catalog captures: firefox 154.0, firefox 155.0.1, firefox 155.0, +6 more.The fingerprint page shows the full measured match list. More on the catalog.1
t13d1517h2_8daaf6152771_3cbfd9057e0d Match?Exact match in Thumbprint's published controlled catalog captures: firefox 155.0.1, firefox 154.0, firefox 156.0, +8 more.The fingerprint page shows the full measured match list. More on the catalog.1

HTTP request (JA4H)

fingerprintco-occurrences
ge20nn020000_b89ce445e0b3_000000000000_000000000000 Match?Exact match in Thumbprint's published controlled catalog captures: go-net/http 1.21.13, go-net/http 1.27.1, go-net/http 1.27.3, +14 more.The fingerprint page shows the full measured match list. More on the catalog.12
ge20nn020000_fb4f949fd323_000000000000_000000000000 Match?Exact match in Thumbprint's published controlled catalog captures: powershell 7.6.6, powershell 7.6.9, powershell 7.6.8.The fingerprint page shows the full measured match list. More on the catalog.3
ge20nr11enus_187a9385d229_000000000000_0000000000001
ge20nr12enus_a72b71f519fc_000000000000_0000000000001
ge20nr020000_fb4f949fd323_000000000000_0000000000001
ge20nr020000_b89ce445e0b3_000000000000_0000000000001

HTTP/2 frames (Akamai)

fingerprintco-occurrences
2:0;4:4194304;5:1048576;6:10485760|1073741824|0|a,m,p,s Match?Exact match in Thumbprint's published controlled catalog captures: go-net/http 1.27.1, go-net/http 1.27.3, go-net/http 1.27.0, +1 more.The fingerprint page shows the full measured match list. More on the catalog.9
2:0;4:4194304;5:16384;6:10485760|1073741824|0|a,m,p,s Match?Exact match in Thumbprint's published controlled catalog captures: go-net/http 1.26.6, go-net/http 1.26.10, go-net/http 1.26.9, +8 more.The fingerprint page shows the full measured match list. More on the catalog.8
1:65536;2:0;4:131072;5:16384|12517377|3:0:0:42|m,p,a,s Match?Exact match in Thumbprint's published controlled catalog captures: firefox 154.0, firefox 152.0.5, firefox 152.0.1, +3 more.The fingerprint page shows the full measured match list. More on the catalog.1
1:65536;2:0;4:131072;5:16384|12517377|3:0:0:22|m,p,a,s Match?Exact match in Thumbprint's published controlled catalog captures: firefox 153.0, firefox 153.0.3, firefox 155.0.1, +32 more.The fingerprint page shows the full measured match list. More on the catalog.1

TCP SYN (p0f)

fingerprintco-occurrences
4:51+13:0:1280:mss*51,10:mss,sok,ts,nop,ws:df,id+:08
4:50+14:0:1280:mss*51,10:mss,sok,ts,nop,ws:df,id+:07
4:49+15:0:1280:mss*51,10:mss,sok,ts,nop,ws:df,id+:02
4:52+12:0:1280:mss*51,10:mss,sok,ts,nop,ws:df,id+:02

User-Agent

fingerprintco-occurrences
Go-http-client/2.013
scrape_central/1.04
Mozilla/5.0 (X11; Linux x86_64; rv:150.0) Gecko/20100101 Firefox/150.02

Country

fingerprintco-occurrences
NL · Netherlands17
DE · Germany2

Network (ASN)

fingerprintco-occurrences
AS39351 · 31173 Services AB10
AS212238 · Datacamp Limited5
AS43357 · Owl Limited2
AS6206 · Netrouting B.V.2

TLS supported groups

fingerprintco-occurrences
11ec,11eb,11ed,001d,0017,0018,0019 Match?Exact match in Thumbprint's published controlled catalog captures: go-net/http 1.27.3, go-net/http 1.26.10.The fingerprint page shows the full measured match list. More on the catalog.4

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
q13d0315h3_55b375c5d22e_dc5437974b471