Open Port Checker
Check whether a TCP port is open on any public host — SSH, HTTP, MySQL, RDP and more — with a live connect test. Free and instant.
Enter a public host and a port to test whether it accepts TCP connections from our server. One host and one port per check.
A closed result can also mean a firewall is silently dropping the connection. This tool checks one port at a time and cannot scan ranges.
О Open Port Checker
The Open Port Checker tests whether a TCP port actually accepts connections on a public host. Enter a hostname or public IP and a port number, and our server opens a plain TCP connection with a short timeout, reporting either open or closed together with the time the handshake took.
One-click presets cover the ports people check most: FTP 21, SSH 22, SMTP 25, DNS 53, HTTP 80, POP3 110, IMAP 143, HTTPS 443, SMTPS 465, submission 587, IMAPS 993, MySQL 3306, RDP 3389, PostgreSQL 5432, Redis 6379, HTTP alt 8080, HTTPS alt 8443 and MongoDB 27017. It is a connect test only — no banner grabbing, no probing of what is behind the port.
By design it can never act as a port scanner: one host and one port per request, tight rate limiting, and a hard refusal of private, reserved or internal addresses. Only test hosts you own or are explicitly authorised to test — unauthorised scanning of third-party infrastructure is illegal in many jurisdictions.
Как использовать Open Port Checker
- Enter the public hostname or IP address you want to test, for example example.com.
- Type the port number, or click one of the common-port presets to fill it in.
- Click “Check port” and wait for the connection attempt to finish or time out.
- Read the verdict — open means the port accepted a TCP connection, closed means it did not — and the connect time.
- If a port you expect to be open reads closed, check the service is running and that the firewall allows inbound traffic on it.