Port Scanner (TCP/UDP)
Check for open ports on any IP address or domain
Scan Ports
Check for open TCP ports on a domain or IP address.
What is an Online Port Scanner?
A Port Scanner is a network diagnostic tool used to check which TCP or UDP ports are open on a server, computer, or internet-connected device. Each network service (such as websites, email, or databases) uses a specific "port" to communicate.
Why check for open ports?
Checking for open ports is a crucial part of **cybersecurity** and systems administration. Professionals use scans for:
- Security Auditing: Identifying unnecessarily exposed services that could be attack vectors.
- Troubleshooting: Confirming if a service (like a web server on port 80 or 443) is accessible from the outside.
- Firewall Validation: Ensuring firewall rules are correctly blocking or allowing traffic.
Understanding Status: Open, Closed, and Filtered
- Open: The device is accepting connections on this port. A service is listening.
- Closed: The device responded, but indicated no active service on this port.
- Filtered: No response within the timeout. Usually means a firewall is dropping the packets.
Safety and Compliance
The Octovelo Port Scanner uses a secure backend to perform direct connection tests. Only use this tool on your own servers or addresses you have explicit permission to audit.