TCP SYN (p0f)

4:51+13:0:1460:mss*29,12:mss,sok,ts,nop,ws:df,id+:0

first seen 2026-06-15 11:04 · last seen 2026-10-27 18:47 · JSON

Last 7 days (1 observations)

Distinct clients per day (last 30 days, peak 6/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
MSS1460
Window sizemss*29
Window scale12
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
t13d191000_9dc949149365_e7c28522265124
t13d4312h1_c7886603b240_b26ce05bbdd617
t13d251100_b78ed14e2fd0_ab7e3b40a67717
t13d1011h2_18ef40b21276_879711aa9f1615
t13d1517h2_8daaf6152771_cb7bf5808d99 Match?Exact match in Thumbprint's published controlled catalog captures: chrome 152.0.7977.83, chrome 154.0.8037.57, chrome 152.0.7977.64, +24 more.The fingerprint page shows the full measured match list. More on the catalog.11
t12d280900_0df5e5c63df4_5c2ba267272410
t13d131100_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.7
t13d3013h2_1d37bd780c83_8537cf56674e6
t13d1517h2_8daaf6152771_3cbfd9057e0d Match?Exact match in Thumbprint's published controlled catalog captures: firefox 155.0.1, firefox 154.0, firefox 156.0, +7 more.The fingerprint page shows the full measured match list. More on the catalog.6
t13d3208h2_a3c911483b05_0deb43056c765

HTTP request (JA4H)

fingerprintco-occurrences
ge11nn040000_8391bea91fb6_000000000000_00000000000025
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.17
ge11nn050000_57c5e92682a8_000000000000_00000000000010
ge10nr040000_532a1ee47909_000000000000_00000000000010
ge20nn020000_5594a17e7e7e_000000000000_000000000000 Match?Exact match in Thumbprint's published controlled catalog captures: curl 8.7.1, curl 8.5.0, curl 8.13.0, +11 more.The fingerprint page shows the full measured match list. More on the catalog.9
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, +36 more.The fingerprint page shows the full measured match list. More on the catalog.7
po11nn080000_4e91bb52a450_000000000000_0000000000007
ge20nn030000_bf75ddd0bb29_000000000000_0000000000006
po20nn23enus_91c53b5c6d06_000000000000_0000000000005
po20nn15enus_bef4d4356c13_000000000000_0000000000005

HTTP/2 frames (Akamai)

fingerprintco-occurrences
0|00|0|m,s,a,p15
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.13
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.7
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.7
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.6
3:100;4:10485760;2:0|1048510465|1:1:0:256|m,s,a,p3
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.2
4:16777216|16711681|0|m,p,a,s2
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 26.6.2, safari 26.5, +2 more.The fingerprint page shows the full measured match list. More on the catalog.1
1:65536;2:0;4:131072;5:16384|12517377|1:0:0:42|m,p,a,s1

TCP SYN (JA4T)

fingerprintco-occurrences
42340_2-4-8-1-3_1460_12130

User-Agent

fingerprintco-occurrences
curl/8.7.115
Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/119.0.0.0 Safari/537.3611
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.3610
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/153.0.0.0 Safari/537.369
Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:156.0) Gecko/20100101 Firefox/156.08
curl/8.14.16
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/146.0.0.0 Safari/537.365
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/131.0.0.0 Safari/537.364
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/145.0.0.0 Safari/537.364
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/126.0.0.0 Safari/537.364

Country

fingerprintco-occurrences
NL · Netherlands69
US · United States54
FR · France21
DE · Germany1

Network (ASN)

fingerprintco-occurrences
AS48090 · TECHOFF SRV LIMITED54
AS138997 · Eons Data Communications Limited34
AS211590 · Bucklog SARL15
AS7029 · Windstream Communications LLC13
AS203020 · HostRoyale Technologies Pvt Ltd4
AS211486 · Alferov Aleksey Aleksandrovich4
AS210328 · AO ALMAZ4
AS9009 · M247 Europe SRL3
AS6079 · RCN3
AS218785 · TC DATACENTER LIMITED3

TLS supported groups

fingerprintco-occurrences
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.15
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.6
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

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_178839b6cec12