Portscan

About Portscan

Portscan is a free online port scanner that checks the public IP address of the visitor making the request, with no account, signup, or API key required. It offers a fast scan of 32 common TCP ports that completes in about 20 seconds, and a deep scan covering all 65,535 TCP ports that takes 60 to 300 seconds and includes service version detection via nmap. Results classify each port as open, closed, or filtered, and the site explains what each state means for use cases like port forwarding, home labs, and firewall checks.

The tool only scans the IP address tied to the visitor's own connection; there is no option to enter a different address, and the target cannot be set by user input. It is aimed at individuals diagnosing their own network setups, such as home servers, remote access, mail, or game servers, rather than at scanning third-party systems.

Portscan also provides programmatic access through an API (with polling or a single streaming request, JSON output, no signup or API key) and an MCP server that lets AI agents scan a user's own open ports as a native tool. Scan metadata is logged for 180 days for abuse prevention and legal compliance, detailed results are kept for 24 hours, and a 7-day history of completed scans is available from the same IP. The site uses a self-hosted Plausible instance for analytics and states no data is shared with third parties.

Key features

• Scans the public IP address of the visiting device for open, closed, or filtered TCP ports
• Fast scan checks 32 common ports in about 20 seconds
• Deep scan checks all 65,535 TCP ports in 60-300 seconds with progressive results
• Deep scan includes nmap-based service version detection on open ports
• API access (polling v1 or streaming v2) with JSON output, no signup or API key
• MCP server for scanning your own open ports as a native AI agent tool

Frequently asked questions