How to Check if a Port Is Open: Windows, Mac, Linux & Online
Test if a TCP port is open online with our free port checker, or run nc, nmap, telnet, and Test-NetConnection locally on Windows, macOS, and Linux.
May 31, 2026
8 min read
HTTP/3 & QUIC Monitoring: What Changes and What to Watch
How HTTP/3 and QUIC change monitoring: UDP 443, 0-RTT, connection migration, fallback to HTTP/2, and the new failure modes and metrics you must watch.
May 29, 2026
9 min read
TCP Port Monitoring: Reachability, Alerts, and Service Health
Use TCP port monitoring to detect listener, firewall, routing, and handshake failures, then pair it with protocol checks that prove the service works.
February 22, 2026
10 min read