TCP SYN (JA4T)

65535_2-1-3-1-1-8-4-0-0_1360_6

first seen 2026-07-01 16:04 · last seen 2026-08-31 12:59 · 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 window65535
Option kinds2-1-3-1-1-8-4-0-0
MSS1360
Window scale6

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
t13d1615h2_86a278354501_a54fffd0eb616
t13d1410h2_f98f5dc5c741_4c1ab05529046
t13d2013h2_a09f3c656075_7f0f34a4126d Match?Exact match in Thumbprint's published controlled catalog captures: safari 26.5.2, safari 26.4, safari 26.6.2, +2 more.The fingerprint page shows the full measured match list. More on the catalog.4
t13d171000_5b57614c22b0_78e6aca7449b2
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.2
t13d1516h2_8daaf6152771_02713d6af862 Match?Exact match in Thumbprint's published controlled catalog captures: chromium 131.0.6778.33, chromium 134.0.6998.35, chromium 133.0.6943.16.The fingerprint page shows the full measured match list. More on the catalog.2
t12d380500_10ed599f3404_67a080e8974e2
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.1
t13d3112h2_e8f1e7e78f70_b26ce05bbdd6 Match?Exact match in Thumbprint's published controlled catalog captures: curl 8.5.0, php-curl 7.88.1.The fingerprint page shows the full measured match list. More on the catalog.1
t13d3013h2_1d37bd780c83_8537cf56674e1

HTTP request (JA4H)

fingerprintco-occurrences
ge20nn16enus_c03e27744605_000000000000_0000000000004
ge20nr12enus_54b4638ab28b_000000000000_000000000000 Match?Exact match in Thumbprint's published controlled catalog captures: chrome 150.0.7871.187, chrome 151.0.7922.137, edge 151.0.4129.93, +36 more.The fingerprint page shows the full measured match list. More on the catalog.4
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.3
ge20nr11enus_187a9385d229_000000000000_0000000000002
ge20nn030000_6dac75bd47eb_000000000000_000000000000 Match?Exact match in Thumbprint's published controlled catalog captures: python-httpx 0.28.1.The fingerprint page shows the full measured match list. More on the catalog.2
ge20nr09engb_5ad46a65401a_000000000000_0000000000002
ge11nn06enus_a89d28968959_000000000000_0000000000002
he11nn030000_58c83775e1a3_000000000000_0000000000001
ge11nn030000_58c83775e1a3_000000000000_0000000000001
ge20nn05enus_3f99bc624e90_000000000000_000000000000 Match?Exact match in Thumbprint's published controlled catalog captures: urlsession 6.3.2, urlsession 6.3.3.The fingerprint page shows the full measured match list. More on the catalog.1

HTTP/2 frames (Akamai)

fingerprintco-occurrences
1:4096;2:0;3:100;4:6291456;5:16384;6:65535|2147418112|1:0:0:220|m,a,s,p4
2:0;3:100;4:2097152;9:1|10420225|0|m,s,a,p Match?Exact match in Thumbprint's published controlled catalog captures: safari 26.5.2, safari 26.5, safari 26.4, +2 more.The fingerprint page shows the full measured match list. More on the catalog.3
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;4:131072;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
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.2
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.2
1:4096;2:0;3:100;4:6291456;5:16384;6:65535|2147418112|1:0:0:256|m,a,s,p2
2:0;4:2097152;3:100;9:1|10485760|0|m,s,p,a1
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.1
1:65536;2:0;4:131072;5:16384|12517377|5:0:0:42|m,p,a,s1

TCP SYN (p0f)

fingerprintco-occurrences
4:52+12:0:1360:65535,6:mss,nop,ws,nop,nop,ts,sok,eol+1:df,id+:010
4:42+22:0:1360:65535,6:mss,nop,ws,nop,nop,ts,sok,eol+1:df,ecn:06
6:38+26:0:1360:65535,6:mss,nop,ws,nop,nop,ts,sok,eol+1:ecn,flow:03
4:45+19:0:1360:65535,6:mss,nop,ws,nop,nop,ts,sok,eol+1:df:02
4:113+15:0:1360:65535,6:mss,nop,ws,nop,nop,ts,sok,eol+1:df:02
4:50+14:0:1360:65535,6:mss,nop,ws,nop,nop,ts,sok,eol+1:id-,ecn:02
4:50+14:0:1360:65535,6:mss,nop,ws,nop,nop,ts,sok,eol+1:id-:02
4:55+9:0:1360:65535,6:mss,nop,ws,nop,nop,ts,sok,eol+1:df,ecn:01
4:46+18:0:1360:65535,6:mss,nop,ws,nop,nop,ts,sok,eol+1:df,ecn:01

User-Agent

fingerprintco-occurrences
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/148.0.0.0 Safari/537.366
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/151.0.0.0 Safari/537.36 Edg/151.0.0.06
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/27.0 Safari/605.1.153
Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:152.0) Gecko/20100101 Firefox/152.02
Goguma (+https://codeberg.org/emersion/goguma)2
tls-client/1.0.12
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/125.0.0.0 Safari/537.361
curl/8.7.11
curl/8.5.01
HackerNews/1567 CFNetwork/3860.300.31 Darwin/25.2.01

Country

fingerprintco-occurrences
TR · Turkey10
NL · Netherlands6
US · United States3
BR · Brazil3
HU · Hungary2
IL · Israel2
AM · Armenia2
SG · Singapore1

Network (ASN)

fingerprintco-occurrences
AS212238 · Datacamp Limited10
AS3917 · Shell Information Technology International B.V.6
AS262539 · DUNET LTDA3
AS12400 · Partner Communications Ltd.2
AS213155 · Yettel Hungary Ltd.2
AS12297 · Telecom Armenia AS2
AS7224 · Amazon.com, Inc.2
AS11251 · Disney Streaming Services1
AS393446 · AlphaCore Network LLC1

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_dc5437974b472