TCP SYN (p0f)

4:55+9:0:1460:mss*44,7:mss,sok,ts,nop,ws:df,id+:0

first seen 2026-06-16 14:05 · last seen 2026-10-31 01:00 · JSON

Last 7 days (14441 observations)

Distinct clients per day (last 30 days, peak 289/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 TTL55+9
Options length0
MSS1460
Window sizemss*44
Window scale7
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
t13d1011h2_61a7ad8aa9b6_f9531d972513 Match?Exact match in Thumbprint's published controlled catalog captures: rust-reqwest 0.13.4, rust-hyper 1.11.0, rust-hyper 1.11.1, +1 more.The fingerprint page shows the full measured match list. More on the catalog.14303
t13d1516h2_8daaf6152771_806a8c22fdea Match?Exact match in Thumbprint's published controlled catalog captures: chrome 150.0.7871.187, chrome 151.0.7922.137, chromium 151.0.7922.34, +28 more.The fingerprint page shows the full measured match list. More on the catalog.878
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.482
t13d301000_1d37bd780c83_3550537cd59b461
t13d3013h2_1d37bd780c83_8537cf56674e276
t12d330600_5172cef6ed69_021165082e1c139
t13d751100_479067518aa3_d41ae481755e134
t13d4312h1_c7886603b240_b26ce05bbdd647
t13d1713h1_ab0a1bf427ad_ecd0401ec68b 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.37
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.25

HTTP request (JA4H)

fingerprintco-occurrences
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.883
ge11nr08enus_002f1ef91713_000000000000_000000000000445
ge20nn11enus_dbdd560af68b_000000000000_000000000000426
ge20nn030000_bf75ddd0bb29_000000000000_000000000000273
ge11nr040000_e1d2031bdfea_000000000000_000000000000166
ge10nn020000_d5c75abc5c2c_000000000000_000000000000134
ge20nn04enus_989c7cc05c9b_000000000000_000000000000128
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.51
ge20nr13enus_0c2c1d640f3e_000000000000_00000000000036
ge20nn09enus_09d949fbb1cf_000000000000_00000000000035

HTTP/2 frames (Akamai)

fingerprintco-occurrences
2:0;4:2097152;5:16384;6:16384|5177345|0|m,s,a,p Match?Exact match in Thumbprint's published controlled catalog captures: rust-reqwest 0.12.28, rust-reqwest 0.13.5, rust-reqwest 0.13.4, +4 more.The fingerprint page shows the full measured match list. More on the catalog.14304
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.895
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.474
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.277
1:65536;2:0;4:6291456;6:262144;4:1048576|15663105|1:0:0:256|m,a,s,p128
4:16777216|16711681|0|m,p,a,s10
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.8
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, curl 7.88.1.The fingerprint page shows the full measured match list. More on the catalog.7
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.3
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, +31 more.The fingerprint page shows the full measured match list. More on the catalog.3

TCP SYN (JA4T)

fingerprintco-occurrences
64240_2-4-8-1-3_1460_717128

User-Agent

fingerprintco-occurrences
Mozilla/5.0 (compatible; ExaSearchBot/1.0; +https://crawler.exa.ai/)14263
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/150.0.0.0 Safari/537.36877
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/124.0.0.0 Safari/537.36449
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/142.0.0.0 Safari/537.36433
curl/8.14.1275
Mozilla/5.0 AppleWebKit/537.36 (KHTML, like Gecko) Chrome/123.0.6312.86 Safari/537.36155
Mozilla/5.0 (compatible; ExaUser/1.0; +https://crawler.exa.ai/exauser)40
Mozilla/5.0 (compatible; ElevenlabsCrawler/1.0; +https://elevenlabs.io/docs/bots)34
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.3619
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/145.0.0.0 Safari/537.3617

Country

fingerprintco-occurrences
US · United States15860
FR · France469
NL · Netherlands198
CA · Canada146
DE · Germany128
GB · United Kingdom101
SE · Sweden86
IT · Italy26
RO · Romania23
CH · Switzerland19

Network (ASN)

fingerprintco-occurrences
AS30058 · FDCservers.net15032
AS51167 · Contabo GmbH467
AS211680 · NSEC - Sistemas Informaticos, S.A.153
AS21859 · Zenlayer Inc153
AS40021 · Contabo Inc.140
AS9009 · M247 Europe SRL114
AS212238 · Datacamp Limited111
AS210906 · UAB Bite Lietuva105
AS396319 · Oxylabs104
AS198093 · Foreningen for digitala fri- och rattigheter83

TLS supported groups

fingerprintco-occurrences
001d,0017,0018 Match?Exact match in Thumbprint's published controlled catalog captures: rust-reqwest 0.12.28, rust-reqwest 0.11.27, powershell 7.6.8, +1 more.The fingerprint page shows the full measured match list. More on the catalog.14304
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.309
001d,0017,001e,0019,0018,0100,0101,0102,0103,0104 Match?Exact match in Thumbprint's published controlled catalog captures: php-guzzle 8.3.1, curl 7.88.1, curl 8.13.0, +10 more.The fingerprint page shows the full measured match list. More on the catalog.145
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.100
0017,0018,001927
11ec,001d,0017,0018,0019 Match?Exact match in Thumbprint's published controlled catalog captures: firefox 157.0.1, firefox-esr 153.5.1esr, firefox 158.0.1, +3 more.The fingerprint page shows the full measured match list. More on the catalog.8
001d,0017,001e,0019,00184
0a0a,001d,0017,00181
001d,0017,0018,0019 Match?Exact match in Thumbprint's published controlled catalog captures: go-net/http 1.21.13.The fingerprint page shows the full measured match list. More on the catalog.1

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_178839b6cec14
q13d0311h3_55b375c5d22e_653d80c3fe9d3