Check if a port is open on a server or a domain.
The port checker tries to open a TCP connection to the ports you list on a server or domain, all at once, and tells you which ones are open, closed or filtered by a firewall, with the response time.
Use it to check that a web, mail, SSH or database server is reachable from the internet, or that a port you closed really is closed.
Tested in parallel.
HTTP, HTTPS, SSH, FTP, SMTP, MySQL and more.
How fast each open port answered.
Private and local addresses are refused.
A program on the server is listening on that port and accepts connections.
Nothing listens on it, or a firewall blocks it. Some hosts only allow certain locations.
80 for HTTP and 443 for HTTPS.