TCP SYN (JA4T)

42340_2-4-8-1-3_1460_12

first seen 2026-06-30 13:03 · last seen 2026-11-01 15:03 · JSON

Last 7 days (158 observations)

Distinct clients per day (last 30 days, peak 719/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 window42340
Option kinds2-4-8-1-3
MSS1460
Window scale12

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
t13d3013h2_1d37bd780c83_8537cf56674e Match?Exact match in Thumbprint's published controlled catalog captures: curl 8.18.0.The fingerprint page shows the full measured match list. More on the catalog.750
t13d191000_9dc949149365_e7c285222651164
t13d131000_f57a46bbacb6_e7c285222651 Match?Exact match in Thumbprint's published controlled catalog captures: go-net/http 1.23.12.The fingerprint page shows the full measured match list. More on the catalog.121
t12d280900_0df5e5c63df4_5c2ba2672724112
t12d4906h1_730fb1b0ac6a_22a92d800fe492
t13d131100_f57a46bbacb6_ab7e3b40a677 Match?Exact match in Thumbprint's published controlled catalog captures: go-net/http 1.26.6, go-net/http 1.26.5, go-net/http 1.26.4.The fingerprint page shows the full measured match list. More on the catalog.74
t13d1517h2_8daaf6152771_cb7bf5808d99 Match?Exact match in Thumbprint's published controlled catalog captures: chrome 152.0.7977.83, chrome 156.0.8078.48, chrome 154.0.8037.57, +27 more.The fingerprint page shows the full measured match list. More on the catalog.63
t13d251100_b78ed14e2fd0_ab7e3b40a67752
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.51
t13d4312h1_c7886603b240_b26ce05bbdd642

HTTP request (JA4H)

fingerprintco-occurrences
ge20nn030000_bf75ddd0bb29_000000000000_000000000000750
ge11nn040000_8391bea91fb6_000000000000_000000000000171
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.135
ge10nr040000_532a1ee47909_000000000000_000000000000112
ge11nn050000_57c5e92682a8_000000000000_00000000000055
ge11nr030000_cd680697de12_000000000000_00000000000045
ge11nn030000_cd680697de12_000000000000_000000000000 Match?Exact match in Thumbprint's published controlled catalog captures: powershell 7.6.6, powershell 7.6.5, powershell 7.6.4, +11 more.The fingerprint page shows the full measured match list. More on the catalog.32
ge20nn14enus_068ebe3632ec_000000000000_00000000000031
ge11nn130000_7f254152a55f_000000000000_00000000000031
ge20nn13enus_0c2c1d640f3e_000000000000_000000000000 Match?Exact match in Thumbprint's published controlled catalog captures: chrome 151.0.7922.137, chrome 151.0.7922.170, chrome 151.0.7922.108, +39 more.The fingerprint page shows the full measured match list. More on the catalog.25

HTTP/2 frames (Akamai)

fingerprintco-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.752
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.51
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, +60 more.The fingerprint page shows the full measured match list. More on the catalog.44
0|00|0|m,s,a,p34
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, +85 more.The fingerprint page shows the full measured match list. More on the catalog.18
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.9
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.8
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;4:6291456;6:262144|15663105|3:1:0:220|m,a,s,p Match?Exact match in Thumbprint's published controlled catalog captures: chromium 151.0.7922.34, chromium 147.0.7727.15, chromium 145.0.7632.6, +26 more.The fingerprint page shows the full measured match list. More on the catalog.3
1:65536;2:0;4:6291456;6:262144|15663105|5:1:0:220|m,a,s,p Match?Exact match in Thumbprint's published controlled catalog captures: chromium 133.0.6943.16, chrome 156.0.8078.48, chrome 150.0.7871.128, +3 more.The fingerprint page shows the full measured match list. More on the catalog.3

TCP SYN (p0f)

fingerprintco-occurrences
4:48+16:0:1460:mss*29,12:mss,sok,ts,nop,ws:df,id+:0890
4:56+8:0:1460:mss*29,12:mss,sok,ts,nop,ws:df,id+:0288
4:57+7:0:1460:mss*29,12:mss,sok,ts,nop,ws:df,id+:0212
4:51+13:0:1460:mss*29,12:mss,sok,ts,nop,ws:df,id+:0130
4:55+9:0:1460:mss*29,12:mss,sok,ts,nop,ws:df,id+:045
4:46+18:0:1460:mss*29,12:mss,sok,ts,nop,ws:df,id+:029
4:50+14:0:1460:mss*29,12:mss,sok,ts,nop,ws:df,id+:028
4:52+12:0:1460:mss*29,12:mss,sok,ts,nop,ws:df,id+:028
4:54+10:0:1460:mss*29,12:mss,sok,ts,nop,ws:df,id+:025
4:49+15:0:1460:mss*29,12:mss,sok,ts,nop,ws:df,id+:024

User-Agent

fingerprintco-occurrences
curl/8.14.1750
Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/119.0.0.0 Safari/537.36113
python-requests/2.27.176
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/126.0.0.0 Safari/537.3653
curl/8.7.146
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/131.0.0.0 Safari/537.3633
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/131.0.0.0 Safari/537.3632
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/155.0.0.0 Safari/537.3630
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.3627
Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/131.0.0.0 Safari/537.3625

Country

fingerprintco-occurrences
NL · Netherlands821
DE · Germany648
US · United States128
FR · France62
SG · Singapore28
EE · Estonia24
CA · Canada12
RO · Romania10
GB · United Kingdom8
IT · Italy3

Network (ASN)

fingerprintco-occurrences
AS211619 · MAXKO d.o.o.639
AS48090 · TECHOFF SRV LIMITED546
AS49870 · Alsycon B.V.92
AS138997 · Eons Data Communications Limited58
AS211486 · Alferov Aleksey Aleksandrovich45
AS9009 · M247 Europe SRL40
AS211590 · Bucklog SARL34
AS205997 · Vlad Cojuhari28
AS7029 · Windstream Communications LLC26
AS213474 · HomeLine Broadband LLC25

TLS supported groups

fingerprintco-occurrences
11ec,001d,0017,001e,0018,0019,0100,0101 Match?Exact match in Thumbprint's published controlled catalog captures: python-httpx 0.28.1, python-requests 2.34.2, curl 8.23.0, +4 more.The fingerprint page shows the full measured match list. More on the catalog.751
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.94
001d,0017,0018,0019 Match?Exact match in Thumbprint's published controlled catalog captures: go-net/http 1.21.13, curl 8.7.1.The fingerprint page shows the full measured match list. More on the catalog.71
11ec,001d,0017,0018,0019 Match?Exact match in Thumbprint's published controlled catalog captures: firefox 158.0.1, firefox 157.0, firefox 157.0.1, +5 more.The fingerprint page shows the full measured match list. More on the catalog.50
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.47
0a0a,11ec,001d,0017,0018 Match?Exact match in Thumbprint's published controlled catalog captures: chrome 156.0.8078.48, edge 155.0.4283.62, chrome 156.0.8078.47, +11 more.The fingerprint page shows the full measured match list. More on the catalog.35
0017,0019,0018,001616
001d,0017,0018,0019,001e,0100,0101,0102,0103,0104 Match?Exact match in Thumbprint's published controlled catalog captures: java-httpclient 17.0.19, java-httpclient 11.0.31, java-urlconnection 17.0.19, +2 more.The fingerprint page shows the full measured match list. More on the catalog.12

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
q13d0312h3_55b375c5d22e_178839b6cec110