Which ports are open?
Enter an IP address or domain to see the state of the ports that matter: remote access (RDP and SSH), web, email, databases and control panels. Handy to confirm a server is up even when it ignores ping.
How it works
How the port check works
IDX Port Checker tries a TCP connection from IDX's server to a fixed list of common ports on the address you enter, all at once, and reports which ones answer.
The ports checked
Remote access (RDP 3389, SSH 22), web (80, 443), email (25, 465, 587, 110, 995, 143, 993), databases (MySQL 3306, SQL Server 1433, PostgreSQL 5432), control panels (cPanel 2083, WHM 2087, Plesk 8443), FTP 21 and DNS 53.
Open, closed or filtered
Open means a service accepted the connection. Closed means the server answered but nothing listens on that port. Filtered means no answer at all, usually a firewall.
No false alarms from one lost packet
Each attempt waits 2.5 seconds, and a port that does not answer is tried once more before it is shown as filtered.
Not a port scanner
Only public addresses and only the fixed list of ports, never ports chosen by the visitor, so the tool cannot be used to scan networks.
Common questions
My database port shows open. Is that a problem?
Usually yes. Database ports such as 3306, 1433 and 5432 should normally be reachable only from your own servers or a VPN, not from the whole internet.
Why does RDP or SSH show filtered?
A firewall is dropping the connection. That is fine if you restricted access on purpose; if you expected it to be open, check the server firewall and your provider's network firewall.
Port 25 is filtered. Can I send email?
Many networks block outgoing and incoming port 25 to fight spam. Mail clients send on 587 or 465 instead; a mail server needs 25 open to receive email.