TCP SYN (p0f)

4:49+15:0:1460:65535,6:mss,nop,ws,nop,nop,ts,sok,eol+1:id-,ecn:0

first seen 2026-06-29 21:21 · last seen 2026-09-14 22:55 · JSON

Matches controlled captures

Known clients driven through this site's own edge produced this exact fingerprint — measured truth, not inference. catalog →

firefox 155.0.1 · macOS 26.6.2 · via geckodriver · ci — 1 session, last 2026-09-14 22:59 controlled
chrome 152.0.7977.83 · macOS 26.6.2 · ci — 1 session, last 2026-09-14 22:55 controlled
curl 8.7.1 · macOS 26.6.2 · ci — 1 session, last 2026-09-07 22:34 controlled
chrome 152.0.7977.65 · macOS 26.6.2 · ci — 1 session, last 2026-09-07 22:29 controlled
safari 26.6.2 · macOS 26.6.2 · ci — 1 session, last 2026-09-07 22:27 controlled
safari 26.6.1 · macOS 15.7.9 · ci — 1 session, last 2026-09-07 22:27 controlled
urlsession 6.1.2 · macOS 15.7.7 · ci — 2 sessions, last 2026-09-01 01:04 controlled
curl 8.7.1 · macOS 15.7.7 · ci — 3 sessions, last 2026-09-01 01:03 controlled
firefox 153.0 · macOS 15.7.7 · via geckodriver · ci — 2 sessions, last 2026-09-01 01:03 controlled
chrome 150.0.7871.187 · macOS 26.5.2 · ci — 5 sessions, last 2026-09-01 00:59 controlled

TCP SYN signatures from container or CI runners reflect the capture environment's kernel and network path, not the named client — the layers above (TLS, HTTP/2, HTTP) are the client's own.

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

IP version	`4`
Initial TTL	`49+15`
Options length	`0`
MSS	`1460`
Window size	`65535`
Window scale	`6`
Options layout	`mss,nop,ws,nop,nop,ts,sok,eol+1`
Quirks	`id-,ecn`
Payload class	`0`

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)

fingerprint	co-occurrences
`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, +24 more.The fingerprint page shows the full measured match list. More on the catalog.	1
`t13d1517h2_8daaf6152771_3cbfd9057e0d` Match?Exact match in Thumbprint's published controlled catalog captures: firefox 154.0, firefox 154.0.1, firefox 155.0.1, +1 more.The fingerprint page shows the full measured match list. More on the catalog.	1

HTTP request (JA4H)

fingerprint	co-occurrences
`ge20nr12en00_54b4638ab28b_000000000000_000000000000`	1
`ge20nr13engb_dee81a311bfc_000000000000_000000000000`	1

HTTP/2 frames (Akamai)

fingerprint	co-occurrences
`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.	1
`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)

fingerprint	co-occurrences
`65535_2-1-3-1-1-8-4-0-0_1460_6`	2

User-Agent

fingerprint	co-occurrences
`Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/150.0.0.0 Safari/537.36`	1
`Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:154.0) Gecko/20100101 Firefox/154.0`	1

Country

fingerprint	co-occurrences
`SG` · Singapore	1
`GB` · United Kingdom	1

Network (ASN)

fingerprint	co-occurrences
`AS56300` · MyRepublic Ltd.	1
`AS16247` · Convergence Group (Wireless) Networks Limited	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).

fingerprint	linked observations
`q13d0311h3_55b375c5d22e_653d80c3fe9d`	1