TCP SYN (JA4T)

65535_2-1-3-1-1-8-4-0-0_1240_6

first seen 2026-07-01 21:43 · last seen 2026-09-12 09:08 · JSON

Last 7 days (5 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
MSS1240
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
t13d2013h2_a09f3c656075_7f0f34a4126d Match?Exact match in Thumbprint's published controlled catalog captures: safari 26.5.2, safari 26.4, safari 26.6.2, +2 more.The fingerprint page shows the full measured match list. More on the catalog.7
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.5
t13d1517h2_8daaf6152771_cb7bf5808d99 Match?Exact match in Thumbprint's published controlled catalog captures: chrome 152.0.7977.83, chrome 152.0.7977.64, chrome 152.0.7977.65, +5 more.The fingerprint page shows the full measured match list. More on the catalog.4
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.1

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.4
ge20nr09engb_5ad46a65401a_000000000000_0000000000002
ge20nr12ja00_54b4638ab28b_000000000000_0000000000002
ge20nr09enus_5ad46a65401a_000000000000_000000000000 Match?Exact match in Thumbprint's published controlled catalog captures: safari 26.5.2, safari 26.4, safari 26.6.2, +2 more.The fingerprint page shows the full measured match list. More on the catalog.1
ge20nr09enca_538441e4e116_000000000000_0000000000001
ge20nn05enus_3f99bc624e90_000000000000_000000000000 Match?Exact match in Thumbprint's published controlled catalog captures: urlsession 6.3.2, urlsession 6.3.3.The fingerprint page shows the full measured match list. More on the catalog.1
ge20nr08engb_1945e0741196_000000000000_0000000000001
ge20nr14enus_093a379182e8_000000000000_0000000000001
ge20nr12ru00_54b4638ab28b_000000000000_0000000000001
ge20nr12ruru_54b4638ab28b_000000000000_0000000000001

HTTP/2 frames (Akamai)

fingerprintco-occurrences
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 26.5, safari 26.4, +2 more.The fingerprint page shows the full measured match list. More on the catalog.6
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.5
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 149.0.7827.102, +59 more.The fingerprint page shows the full measured match list. More on the catalog.4
2:0;4:2097152;3:100;9:1|10485760|0|m,s,p,a1
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, +43 more.The fingerprint page shows the full measured match list. More on the catalog.1

TCP SYN (p0f)

fingerprintco-occurrences
4:49+15:0:1240:65535,6:mss,nop,ws,nop,nop,ts,sok,eol+1:df,ecn:04
4:46+18:0:1240:65535,6:mss,nop,ws,nop,nop,ts,sok,eol+1:df,ecn:03
4:50+14:0:1240:65535,6:mss,nop,ws,nop,nop,ts,sok,eol+1:df,ecn:02
4:48+16:0:1240:65535,6:mss,nop,ws,nop,nop,ts,sok,eol+1:df,ecn:02
4:53+11:0:1240:65535,6:mss,nop,ws,nop,nop,ts,sok,eol+1:df,ecn:01
4:62+2:0:1240:65535,6:mss,nop,ws,nop,nop,ts,sok,eol+1:df,ecn:01
4:55+9:0:1240:65535,6:mss,nop,ws,nop,nop,ts,sok,eol+1:df,ecn:01
6:54+10:0:1240:65535,6:mss,nop,ws,nop,nop,ts,sok,eol+1:ecn,flow:01
4:56+8:0:1240:65535,6:mss,nop,ws,nop,nop,ts,sok,eol+1:df,ecn:01
6:40+24:0:1240:65535,6:mss,nop,ws,nop,nop,ts,sok,eol+1:ecn,flow:01

User-Agent

fingerprintco-occurrences
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/152.0.0.0 Safari/537.364
curl/8.7.13
Mozilla/5.0 (iPhone; CPU iPhone OS 18_6 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/26.5 Mobile/15E148 Safari/604.1 Ddg/26.52
Mozilla/5.01
HackerNews/1566 CFNetwork/3860.600.12 Darwin/25.5.01
Mozilla/5.0 (iPhone; CPU iPhone OS 18_7 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/26.4 Mobile/15E148 Safari/604.11
Mozilla/5.0 (iPhone; CPU iPhone OS 18_7 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/27.0 Mobile/15E148 Safari/604.11
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/26.6 Safari/605.1.151
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/149.0.0.0 Safari/537.36 OPR/133.0.0.01
curl/7.71.1-DEV1

Country

fingerprintco-occurrences
JP · Japan6
US · United States3
NL · Netherlands3
LT · Lithuania2
CA · Canada1
SE · Sweden1
PL · Poland1

Network (ASN)

fingerprintco-occurrences
AS63949 · Akamai Connected Cloud3
AS2527 · Sony Network Communications Inc.3
AS43357 · Owl Limited2
AS399498 · Private Networks Labs LLC2
AS12222 · Akamai Technologies, Inc.2
AS39351 · 31173 Services AB1
AS57043 · HOSTKEY B.V.1
AS7018 · AT&T Enterprises, LLC1
AS11878 · tzulo, inc.1
AS26042 · FiberState, LLC1

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_f2a83c8e78ae4