How to Scan for Open Ports
Web browsers cannot directly scan network ports for security reasons. Use the tools below instead. Share this guide:
⚠️ **Warning:** Only scan devices and networks you have explicit permission to test. Unauthorized scanning can be illegal.
Using Nmap (Recommended)
Nmap ("Network Mapper") is the industry standard tool for network discovery and security auditing.
Installation
Download the official Nmap installer for your OS:
Basic Port Scanning Commands
Open your command prompt (Windows) or terminal (macOS/Linux):
- Scan common ports:
nmap target.com - Scan all TCP ports (slower):
nmap -p- target.com - Scan specific ports (e.g., 80, 443):
nmap -p 80,443 target.com - Scan your own computer:
nmap localhost - OS/Service detection (intrusive):
sudo nmap -A target.com
Using Built-in OS Tools (Check Listening Ports on Your PC)
Windows (Command Prompt)
netstat -ano | findstr "LISTENING"macOS / Linux (Terminal)
sudo netstat -lntpOr using `ss` (modern Linux):
sudo ss -lntp