If you are hosting your web applications on managed or shared server, then you don’t have to worry about it.

However, for VPS or dedicated, you must consider doing all it takes to secure your server.

Having unwanted ports opened is a lousy idea; an attacker can take advantage of it in many ways.


Here are online FREE tools, which will help you to find out what all ports are opened so you can review and block them if not needed.

Note: if you’re running a port scan on your website DNS and if that is behind the cloud proxy like Cloudflare or SUCURI, then it may not give you the accurate information.

TCP Port Scan with Nmap

Pentest Tools check open ports using NMAP on the targeted host.

In the light version, there is some limitation like it scan for up-to 100 top ports, single IP only. However, if you go for a full scan, then you can scan all 65,535 ports, detect OS and traceroute. And, if you need to export the scan results, then you can do so.

Geekflare’s Port Scanner API

Alternatively, you can try Geekflare Port Scanner API. It lists all the open ports on your website or IP within seconds.

geekflare port scanner api

But what’s even better is the free plan, which you can use for 3000 API requests without paying a penny. And should you feel to upgrade, premium ones start with 10K API calls for just $5 a month.

Online Port Scanner

This tool is a personal project of Javier Yanez, available to use in free to scan the ports against IPV4 or IPV6 address.


Port Scanner by Hacker Target

Hacker Target lets you perform a quick scan with most standard following ten ports with a hosted NMAP port scanner.

  • FTP
  • SSH
  • SMTP
  • HTTP
  • RDP
  • POP3
  • IMAP
  • SMB
  • Telnet

They also got a premium version that offers the following.

  • Scan all ports
  • Scan on subnet
  • Schedule to run a daily scan and get notified for any changes

Port Scanner by DNS Tools

Quickly scan for some of the standard ports like FTP, SMTP, DNS, Finger, POP3, SFTP, RPC, IRC, IMAP, VNC, etc. through DNS Tools.



You can test for an individual port or by a package is free. However, for more like scanning the range of custom, you need to subscribe to their service.

The package is nothing but a group of relevant ports.

  • Basic – HTTP, POP3, MySQL, etc
  • Web – cPanel, DNS, WHOIS, TrelliSoft, TFTP, etc
  • Games – Call of Duty, Second Life, Xbox, Minecraft, etc
  • Malicious – Metaspoilt, Bagle virus, W32, etc

Web Port Scanner

Another scanner to check for common ports.


I hope the above tools help to find the opened ports on your domain or IP. Most of the web tools will have some limitations, so if you are looking for a heavy use port scanner, I would recommend using the software mentioned here. As you can notice, Nmap is an essential tool to scan the ports, and if you are looking to learn more about it, then check out this fantastic network security course.