Portscan

About Portscan

Portscan is a free online port scanner that checks the TCP ports of the public IP address a visitor's request originates from. It requires no account, signup, or API key. Two scan modes are offered: a fast scan that checks 32 common TCP ports in about 20 seconds, and a deep scan that checks all 65,535 TCP ports in 60 to 300 seconds, including service version detection via nmap for open ports found. Results classify each port as open, closed, or filtered, with explanations of what each state means.

The scan target is determined server-side from the connection and cannot be set to another address, so only the requester's own IP is scanned. The tool is aimed at diagnostics such as checking port forwarding, home lab setups, firewall configuration, and identifying unintentionally exposed services like databases or remote access ports. It also provides an abuse-contact page listing scanner IP addresses and verification methods, and an opt-out mechanism to exclude an IP or CIDR range from future scans.

For automation, portscan.com offers an API (polling v1 or a streaming v2 request) that returns JSON without requiring a signup or API key, and an MCP server that lets AI agents scan their own open ports as a native tool, also without a key or signup. Scan metadata is logged for 180 days for abuse prevention and legal compliance under German law, detailed results are kept for 24 hours, and a 7-day scan history is visible from the same IP. The site uses a self-hosted Plausible analytics instance that collects aggregate page views without cookies or personal data, and states no data is shared with third parties.

Key features

• Fast scan checks 32 common TCP ports in about 20 seconds
• Deep scan checks all 65,535 TCP ports with nmap-based service version detection
• Scans run against the requester's own public IP, determined server-side with no user input
• REST API (v1 polling, v2 streaming) for scanning from scripts and pipelines, no API key or signup
• MCP server for scanning open ports as a native tool in AI agents
• 7-day history of completed scans viewable from the same IP

Frequently asked questions