TCP SYN (JA4T)

64480_2-4-8-1-3_1240_10

first seen 2026-07-06 14:01 · last seen 2026-08-31 15:11 · 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 window64480
Option kinds2-4-8-1-3
MSS1240
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
t13d1617h2_86a278354501_3cbfd9057e0d Match?Exact match in Thumbprint's published controlled catalog captures: firefox 153.0, firefox 153.0.3, firefox 152.0.3, +10 more.The fingerprint page shows the full measured match list. More on the catalog.5
t13d1516h2_8daaf6152771_806a8c22fdea Match?Exact match in Thumbprint's published controlled catalog captures: chrome 150.0.7871.187, chrome 151.0.7922.137, chromium 151.0.7922.34, +24 more.The fingerprint page shows the full measured match list. More on the catalog.2
t13d3013h2_1d37bd780c83_8537cf56674e2
t13d1617h2_86a278354501_3e9721a6796e1

HTTP request (JA4H)

fingerprintco-occurrences
ge20nr12enus_979a40433f82_000000000000_0000000000004
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.2
ge20nn13enus_016d87568c43_000000000000_0000000000001
ge20nn14engb_e7796bbdab6f_000000000000_0000000000001
ge20nn16engb_aedc7d5591f1_000000000000_0000000000001
ge20nr11engb_187a9385d229_000000000000_0000000000001

HTTP/2 frames (Akamai)

fingerprintco-occurrences
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 154.0, +25 more.The fingerprint page shows the full measured match list. More on the catalog.3
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.2
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|7:0:0:22|m,p,a,s Match?Exact match in Thumbprint's published controlled catalog captures: firefox 153.0.3, firefox 155.0, firefox 154.0, +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|5:0:0:22|m,p,a,s Match?Exact match in Thumbprint's published controlled catalog captures: firefox 153.0.3, firefox 154.0, firefox 153.0, +8 more.The fingerprint page shows the full measured match list. More on the catalog.1
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, +43 more.The fingerprint page shows the full measured match list. More on the catalog.1
1:65536;2:0;4:6291456;6:262144|15663105|5:1:0:256|m,a,s,p1

TCP SYN (p0f)

fingerprintco-occurrences
4:55+9:0:1240:mss*52,10:mss,sok,ts,nop,ws:df,id+:05
4:51+13:0:1240:mss*52,10:mss,sok,ts,nop,ws:df,id+:02
4:50+14:0:1240:mss*52,10:mss,sok,ts,nop,ws:df,id+:01
4:42+22:0:1240:mss*52,10:mss,sok,ts,nop,ws:df,id+:01
4:46+18:0:1240:mss*52,10:mss,sok,ts,nop,ws:df,id+:01

User-Agent

fingerprintco-occurrences
Mozilla/5.0 (X11; Linux x86_64; rv:152.0) Gecko/20100101 Firefox/152.05
curl/8.21.02
Mozilla/5.0 (iPhone; CPU iPhone OS 18_5 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/18.5 Mobile/15E148 Safari/604.11
Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/150.0.0.0 Safari/537.361
Mozilla/5.0 (X11; Linux x86_64; rv:153.0) Gecko/20100101 Firefox/153.01

Country

fingerprintco-occurrences
US · United States5
DE · Germany3
GB · United Kingdom1
CZ · Czechia1

Network (ASN)

fingerprintco-occurrences
AS136557 · Host Universal Pty Ltd5
AS31898 · Oracle Corporation3
AS8560 · IONOS SE1
AS49985 · IP4ISP z.s.p.o1

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_78345df32b3a1