Live test 01 · Passive

TCP/IP fingerprint

Your TCP/IP fingerprint is captured passively from the SYN packet of your connection. It reveals your operating system without any client-side JavaScript.

Your connection

Capturing your TCP/IP fingerprint…

Raw TCP/IP fingerprint

Field reference

Field	Description
tcp_options	TCP options string from the SYN packet
ip_total_length	Total length of the IP packet (bytes)
tcp_window_size	TCP initial window size
tcp_window_scaling	TCP window scale factor
tcp_mss	TCP Maximum Segment Size
tcp_off	TCP data offset (header length / 4)
tcp_flags	TCP flags as integer (SYN = 2)
tcp_timestamp	TCP timestamp value from options
ip_ttl	IP Time To Live
ip_tos	IP Type of Service / DSCP
ip_id	IP Identification field

TCP/IP fingerprint

OS classification scores

Raw TCP/IP fingerprint

Field reference