TCP SYN (p0f)

4:52+12:0:1460:mss*29,10:mss,sok,ts,nop,ws:df,id+:0

first seen 2026-07-18 15:57 · last seen 2026-10-23 22:46 · JSON

Distinct clients per day (last 30 days, peak 2/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 TTL52+12
Options length0
MSS1460
Window sizemss*29
Window scale10
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
t13d1011h1_61a7ad8aa9b6_3a8073edd8ef27
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.2
t13d190900_9dc949149365_97f8aa674fd91

HTTP request (JA4H)

fingerprintco-occurrences
ge11nr040000_8b1ed2202073_000000000000_00000000000027
ge20nn030000_bf75ddd0bb29_000000000000_0000000000002
ge11nn040000_e1d2031bdfea_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.2

TCP SYN (JA4T)

fingerprintco-occurrences
42340_2-4-8-1-3_1460_1030

User-Agent

fingerprintco-occurrences
Mozilla/5.0 (compatible; Applebot/0.1; +http://www.apple.com/go/applebot)3
Mozilla/5.0 (compatible; YandexBot/3.0; +http://yandex.com/bots)2
curl/8.14.12
Mozilla/5.0 (compatible; OAI-SearchBot/1.3; +https://openai.com/searchbot)2
Mozilla/5.0 (compatible; bingbot/2.0; +http://www.bing.com/bingbot.htm)2
CCBot/2.0 (https://commoncrawl.org/faq/)2
Mozilla/5.0 (compatible; Google-CloudVertexBot; +https://cloud.google.com/vertex-ai-bot)2
Mozilla/5.0 AppleWebKit/537.36 (KHTML, like Gecko; compatible; GPTBot/1.3; +https://openai.com/gptbot)2
Mozilla/5.0 (compatible; PerplexityBot/1.0; +https://perplexity.ai/perplexitybot)2
Mozilla/5.0 AppleWebKit/537.36 (KHTML, like Gecko; compatible; ChatGPT-User/1.0; +https://openai.com/bot)2

Country

fingerprintco-occurrences
CH · Switzerland27
JP · Japan2
HK · Hong Kong SAR China1

Network (ASN)

fingerprintco-occurrences
AS53667 · FranTech Solutions27
AS20473 · The Constant Company, LLC2
AS398722 · Censys, Inc.1

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.2