TCP SYN (JA4T)
65535_2-4-8-1-3_1380_13
first seen 2026-07-01 03:37 · last seen 2026-10-28 21:02 · JSON
Last 7 days (4 observations)
Distinct clients per day (last 30 days, peak 406/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 window | 65535 |
|---|---|
| Option kinds | 2-4-8-1-3 |
| MSS | 1380 |
| Window scale | 13 |
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)
| fingerprint | co-occurrences |
|---|---|
t13d3013h2_1d37bd780c83_8537cf56674e | 427 |
t13d1011h1_61a7ad8aa9b6_3a8073edd8ef | 93 |
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. | 72 |
t13d180900_796efca44d18_1497af28dee9 | 7 |
t13d1511h2_8daaf6152771_78e6aca7449b | 6 |
t13d3013h1_1d37bd780c83_8537cf56674e | 4 |
t13i3111h1_e8f1e7e78f70_b26ce05bbdd6 | 3 |
t13d4907h2_0d8feac7bc37_7395dae3b2f3 Match?Exact match in Thumbprint's published controlled catalog captures: curl 8.7.1.The fingerprint page shows the full measured match list. More on the catalog. | 2 |
t13d301200_1d37bd780c83_ecd0401ec68b | 2 |
t13d1518h2_8daaf6152771_4980c97edce0 | 2 |
HTTP request (JA4H)
| fingerprint | co-occurrences |
|---|---|
ge20nn030000_bf75ddd0bb29_000000000000_000000000000 | 424 |
ge11nr04enus_3adac55f58e9_000000000000_000000000000 | 23 |
ge20nn020000_fb4f949fd323_000000000000_000000000000 Match?Exact match in Thumbprint's published controlled catalog captures: powershell 7.6.6, powershell 7.6.8.The fingerprint page shows the full measured match list. More on the catalog. | 15 |
ge11nr11enus_1fab05156ead_000000000000_000000000000 | 9 |
ge11nr13enus_ed40770a2e50_000000000000_000000000000 | 9 |
ge11nr05enus_3bd45b6f184e_000000000000_000000000000 | 8 |
ge11nr06enus_85f58504866d_000000000000_000000000000 | 7 |
he11nr04enus_3adac55f58e9_000000000000_000000000000 | 7 |
ge11nr10enus_e297311195fc_000000000000_000000000000 | 7 |
ge11nn16enus_0d6ca22ab264_000000000000_000000000000 | 6 |
HTTP/2 frames (Akamai)
| fingerprint | co-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. | 427 |
2:0;4:4194304;5:16384;6:262144;1:65536|1073741824|0|a,m,p,s | 47 |
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. | 22 |
2:0;4:2097152;5:16384;6:16777216|5177345|0|m,s,a,p | 6 |
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. | 5 |
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, +31 more.The fingerprint page shows the full measured match list. More on the catalog. | 3 |
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. | 2 |
3:100;4:10485760;2:0|1048510465|0|m,s,a,p Match?Exact match in Thumbprint's published controlled catalog captures: curl 8.7.1, curl 8.5.0.The fingerprint page shows the full measured match list. More on the catalog. | 2 |
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. | 1 |
TCP SYN (p0f)
User-Agent
Country
| fingerprint | co-occurrences |
|---|---|
US · United States | 142 |
FR · France | 80 |
JP · Japan | 63 |
SG · Singapore | 50 |
NL · Netherlands | 34 |
DE · Germany | 28 |
GB · United Kingdom | 22 |
RU · Russia | 17 |
FI · Finland | 14 |
ID · Indonesia | 13 |
Network (ASN)
| fingerprint | co-occurrences |
|---|---|
AS13335 · Cloudflare, Inc. | 629 |
TLS supported groups
| fingerprint | co-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. | 424 |
001d,0017,001e,0019,0018,0100,0101,0102,0103,0104 Match?Exact match in Thumbprint's published controlled catalog captures: curl 8.13.0, php-guzzle 8.3.1, curl 7.88.1, +10 more.The fingerprint page shows the full measured match list. More on the catalog. | 3 |
0a0a,11ec,001d,0017,0018 Match?Exact match in Thumbprint's published controlled catalog captures: chrome 155.0.8059.40, chrome 156.0.8078.73, chromium 156.0.8078.47, +8 more.The fingerprint page shows the full measured match list. More on the catalog. | 2 |
001d,0017,0018 Match?Exact match in Thumbprint's published controlled catalog captures: rust-reqwest 0.12.28, rust-reqwest 0.11.27, powershell 7.6.8, +1 more.The fingerprint page shows the full measured match list. More on the catalog. | 1 |
11ec,6399,001d,fe32,0017,0018,0019 | 1 |
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).
| fingerprint | linked observations |
|---|---|
q13d0315h3_55b375c5d22e_dc5437974b47 | 2 |
q13d0315h3_55b375c5d22e_bb76f32061e3 | 1 |