A port is a virtual endpoint for network communication. Different services listen on specific ports — HTTP on 80, HTTPS on 443, SSH on 22, FTP on 21. Checking if a port is open tells you whether that service is accessible from the internet.

What does an open port mean?

An open port means a service is listening and accepting connections on that port from the network. A closed port means no service is listening, or a firewall is blocking it.

Why can browsers only test HTTP/HTTPS ports?

Browser security prevents raw TCP connections. The browser can only make HTTP/HTTPS requests, so only ports that serve HTTP content (80, 443, 8080, 8443) can be tested. For TCP ports like SSH or MySQL, use a command-line tool.

Is port scanning legal?

Port scanning your own servers is perfectly legal. Scanning third-party servers without permission may violate their terms of service or local laws. Always get permission before scanning external systems.

What is the difference between open, closed, and filtered?

Open means the port is accepting connections. Closed means the host is reachable but no service is listening on that port. Filtered means a firewall is blocking the port — no response is received.

Can this tool scan all ports on a server?

No. This tool checks one port at a time. Full port scanning requires dedicated tools and should only be used on infrastructure you own or have authorization to test.

Port Checker — Check if HTTP/HTTPS Ports Are Open Free Online

Check if HTTP or HTTPS ports are open on any hostname or IP address. Test common ports with one click. Free online port checker.

Single portCommon ports

Browser limitation: Only HTTP/HTTPS ports can be probed from a browser. TCP ports (SSH, FTP, MySQL, etc.) cannot be directly tested and are marked as “not testable”. Use nmap or telnet for full TCP port scanning.

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What is Port Checker — Check if a Port is Open Online Free?

A port checker tests whether a specific TCP port is open and accepting connections on a remote host. HTTP uses port 80, HTTPS uses port 443, SSH uses port 22, FTP uses port 21, and so on. Knowing whether ports are open or closed helps diagnose firewall misconfigurations, verify service availability, and confirm server deployment.

How to Use Port Checker — Check if a Port is Open Online Free

1Enter the hostname or IP address you want to check.
2Enter the port number, or select a common port from the presets.
3Click Check Port to test connectivity.
4See whether the port is open (accepting connections) or closed/filtered.

Key Features

Tests any TCP port on any hostname or IP
Common port presets (80, 443, 22, 21, 25, 3306, etc.)
Open/closed/filtered status
Response time measurement
Instant results

Benefits

Verify firewall rules are allowing the correct ports
Confirm web server is listening on port 80 and 443
Diagnose SSH, FTP, and database connection issues
Check if services are exposed to the internet

Why Use Irreva for Port Checker — Check if a Port is Open Online Free?

Verify firewall rules are allowing the correct ports

Confirm web server is listening on port 80 and 443

Diagnose SSH, FTP, and database connection issues

Runs 100% in your browser — files never leave your device.

No account, no sign-up, no subscription — free forever.

Works on any device: desktop, tablet, or mobile.

Frequently Asked Questions

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