Port Checker
Check if TCP ports are open on a hostname or IP address — enter host:port and see which ports are reachable.
| Port | Service | Status |
|---|
About this tool
Enter a hostname or IP address and a comma-separated list of TCP port numbers. The tool queries a public port-checking API to test whether each port is reachable from the internet, then shows the results in a table with service name hints for well-known ports.
Example: enter example.com with ports
80, 443 — you get a table showing port 80 (HTTP) is open,
port 443 (HTTPS) is open. Try github.com with
22, 80, 443 to see that SSH (22) is typically closed on
public-facing servers.
Click a preset button to fill in common port groups (web, databases, mail, remote desktop), or type your own. Each result row includes the port number, a common service name when recognized, and an Open or Closed badge. The Copy results button exports all rows as tab-separated text.
FAQ
Why do some ports show as closed even though the server is running? ›
A port can be closed for many reasons: a firewall is blocking inbound traffic, the service is bound only to localhost (127.0.0.1), the service is not running, or the hosting provider blocks the port at the network edge. A "closed" result means the API could not establish a TCP connection within the timeout — it does not distinguish an actively rejected connection from a filtered/dropped one.
Can this tool check ports on my local machine (localhost / 127.0.0.1)? ›
No — the port checking API runs from its own servers on the public internet. It can only reach publicly routable IP addresses, not private or loopback addresses like 127.0.0.1, 192.168.x.x, or 10.x.x.x. To check ports on your local machine, use a command-line tool like nc, telnet, or nmap.
How long does each port check take? ›
The API uses a 1-second timeout per port and checks ports sequentially. Checking 5 ports typically completes in under 5 seconds; checking the full "Common ports" set (18 ports) takes about 18–20 seconds. The frontend has a 15-second timeout, so large port lists may time out — use smaller batches if needed.
What do the service names mean? ›
The Service column shows the conventional protocol or application that usually listens on that port number (e.g. port 3306 is MySQL, port 5432 is PostgreSQL). These are hints based on IANA assignments and common usage — the tool does not inspect the actual protocol running on the port. A service name appearing does not mean that particular service is running; it only means the port is open.