TCP SYN (JA4T)

65535_2-1-3-1-1-8-4-0-0_1300_6

first seen 2026-07-04 18:47 · last seen 2026-09-15 06:09 · JSON

Last 7 days (1 observations)

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
MSS1300
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
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.6
t13d1616h2_86a278354501_0c27189014cf Match?Exact match in Thumbprint's published controlled catalog captures: firefox 153.0, firefox 153.0.3, firefox 152.0.6, +10 more.The fingerprint page shows the full measured match list. More on the catalog.2
t13d1812h1_85036bcba153_b26ce05bbdd62
t13d2014h2_a09f3c656075_14788d8d241b1
t13d3113h2_e8f1e7e78f70_1b3407e2c9361

HTTP request (JA4H)

fingerprintco-occurrences
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.7
ge11nn050000_b223a0ebb0b5_000000000000_000000000000 Match?Exact match in Thumbprint's published controlled catalog captures: python-requests 2.34.2, python-requests 2.33.1, python-requests 2.32.3.The fingerprint page shows the full measured match list. More on the catalog.2
ge20nr10ruru_b3034183f430_000000000000_0000000000001
ge20nr11enus_187a9385d229_000000000000_0000000000001
ge20nn05zhcn_eff5d0107a3f_000000000000_0000000000001

HTTP/2 frames (Akamai)

fingerprintco-occurrences
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.6
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
4:2097152;3:100|10485760|0|m,s,p,a1
3:100;4:33554432;2:0|33488897|0|m,p,s,a Match?Exact match in Thumbprint's published controlled catalog captures: php-curl 7.88.1.The fingerprint page shows the full measured match list. More on the catalog.1

TCP SYN (p0f)

fingerprintco-occurrences
4:54+10:0:1300:65535,6:mss,nop,ws,nop,nop,ts,sok,eol+1:df,ecn:06
6:42+22:0:1300:65535,6:mss,nop,ws,nop,nop,ts,sok,eol+1:ecn,flow:02
4:47+17:0:1300:65535,6:mss,nop,ws,nop,nop,ts,sok,eol+1:df:01
4:53+11:0:1300:65535,6:mss,nop,ws,nop,nop,ts,sok,eol+1:df,ecn:01
6:49+15:0:1300:65535,6:mss,nop,ws,nop,nop,ts,sok,eol+1:flow:01
6:54+10:0:1300:65535,6:mss,nop,ws,nop,nop,ts,sok,eol+1:flow:01

User-Agent

fingerprintco-occurrences
curl/8.7.15
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 Chrome/124 Safari/537.362
Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:152.0) Gecko/20100101 Firefox/152.01
Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:153.0) Gecko/20100101 Firefox/153.01
MyTestAgent/9.91
Good1
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/139.0 Safari/537.361

Country

fingerprintco-occurrences
IL · Israel6
IN · India2
RU · Russia1
CN · China1
FI · Finland1
LV · Latvia1

Network (ASN)

fingerprintco-occurrences
AS208905 · Exelera Telecom Ltd6
AS55836 · Reliance Jio Infocomm Limited2
AS12389 · PJSC Rostelecom1
AS4812 · China Telecom (Group)1
AS210546 · CHSL ONE LTD1
AS59967 · SIA EVOLUTION LATVIA1

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