TCP SYN (p0f)

4:51+13:0:1380:65535,13:mss,sok,ts,nop,ws:df,id+:0

first seen 2026-06-20 18:53 · last seen 2026-10-28 21:02 · JSON

Last 7 days (1 observations)

Distinct clients per day (last 30 days, peak 115/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

IP version4
Initial TTL51+13
Options length0
MSS1380
Window size65535
Window scale13
Options layoutmss,sok,ts,nop,ws
Quirksdf,id+
Payload class0

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.124
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.68
t12d180700_4b22cbed5bed_2dae41c691ec2
t13d180900_796efca44d18_1497af28dee92
t13i3111h1_e8f1e7e78f70_b26ce05bbdd62
t13d1515h1_8daaf6152771_0a20fe35d3a51
t13d1516h2_8daaf6152771_cd486ad61c781
t13d1517h2_8daaf6152771_68c5a8c2958d1
t13d1616h2_86a278354501_ca3c9f3127701

HTTP request (JA4H)

fingerprintco-occurrences
ge20nn030000_bf75ddd0bb29_000000000000_000000000000124
ge20nn020000_fb4f949fd323_000000000000_000000000000 Match?Exact match in Thumbprint's published controlled catalog captures: powershell 7.6.6, powershell 7.6.9, powershell 7.6.8.The fingerprint page shows the full measured match list. More on the catalog.15
ge11nn040000_cf1edba2959c_000000000000_0000000000002
ge11nn16enus_0d6ca22ab264_000000000000_0000000000002
ge20nr11frfr_187a9385d229_000000000000_0000000000002
ge11nn050000_212a08913770_000000000000_0000000000002
ge20nn11enus_3901d4197baf_000000000000_000000000000 Match?Exact match in Thumbprint's published controlled catalog captures: firefox 154.0, firefox 152.0.5, firefox 153.0.1, +3 more.The fingerprint page shows the full measured match list. More on the catalog.1
ge11nn13enus_9db22d02e17a_000000000000_0000000000001
ge20nn09enus_ceece968ba6c_000000000000_0000000000001
po20nn040000_a1c8fcd1f2bb_000000000000_0000000000001

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.124
2:0;4:4194304;5:16384;6:262144;1:65536|1073741824|0|a,m,p,s47
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.21
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, +32 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

TCP SYN (JA4T)

fingerprintco-occurrences
65535_2-4-8-1-3_1380_13200

User-Agent

fingerprintco-occurrences
curl/8.14.1124
Mozilla/5.0 (compatible; Applebot/0.1; +http://www.apple.com/go/applebot)37
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/149.0.0.0 Safari/537.3611
Mozilla/5.0 (iPhone; CPU iPhone OS 18_1 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Mobile/15E148 DingTalk(2.7.10) com.laiwang.DingTalk/35900215 Channel/201200 language/zh-Hans-CN5
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/119.0.0.0 Safari/537.362
Mozilla/5.0 (compatible; SecurityScanner/1.0)2
Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:154.0) Gecko/20100101 Firefox/154.02
Mozilla/5.0 (compatible; Googlebot/2.1; +http://www.google.com/bot.html)1
Go-http-client/2.01
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/123.0.0.0 Safari/537.361

Country

fingerprintco-occurrences
FR · France68
JP · Japan53
NL · Netherlands22
RU · Russia8
US · United States6
CO · Colombia4
DE · Germany3
VE · Venezuela3
IE · Ireland2
FI · Finland2

Network (ASN)

fingerprintco-occurrences
AS13335 · Cloudflare, Inc.202

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.124
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.2

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