Port Scanner - Scan the ports on an IP address, hostname or network range (Updated Jul 2026)


Description:
Port Scanner checks which TCP and UDP ports are open on a target and identifies the service usually associated with each one. You can point it at a single IP address, a hostname (which it resolves for you), or a whole CIDR range such as 192.168.1.0/24. Choose a ready-made port preset or your own range or list, and fine-tune the scan with an adjustable timeout and thread count for speed. It can ping a host first and skip it if there’s no reply, grab the service banner from open TCP ports for extra detail, and save named scan profiles for re-use. Results appear live in a sortable grid with a running log; you can save a scan as a baseline and later compare against it to spot newly opened or closed ports, and export everything to text, CSV, JSON or a styled HTML report.


How to use:


1. Enter a target. Type an IP address, a hostname, or a CIDR range (for example 192.168.1.0/24) into the Target box. Click Resolve Hostname to turn a hostname into its IP address first if you wish.

2. Choose the ports. Pick a Preset — Custom, Well-Known (1-1023), Common (1-10000) or Full Scan (1-65535) — or, in Custom mode, type a start and end port. To scan only particular ports, enter them in Specific Ports as a comma-separated list (for example 22,80,443,3389,8080), which takes priority over the range.

3. Pick protocols and options. Tick TCP and/or UDP. Optionally tick Ping First (send an ICMP ping and skip hosts that don’t answer) and Banner Grab (read the service banner from open TCP ports for more detail). Adjust Timeout (ms) and Threads to balance speed against reliability.

4. Scan. Click Scan. The progress bar, current-task line and live log track the scan, and each open TCP port or responding UDP port appears in the results grid with its Protocol, Port, Service, State and Notes (including any grabbed banner). Click Cancel to stop early.

5. (Optional) Compare against a baseline. After a scan, click Save Baseline to remember the current open ports. Run the scan again later and click Compare to see which ports are newly open or now closed — useful for spotting changes over time.

6. (Optional) Save a profile. Use Save to store the current ports, protocols, timeout, threads and options as a named profile, and Load to bring a saved profile back later.

7. Export the results. Save the results with the export buttons — TXT, CSV, JSON, or a styled HTML report (with summary cards and a top-services chart) that you can open in your browser.

What You Can Do With This Program

Potential Uses for Port Scanner Tool:

• Network Security Auditing and Vulnerability Assessment:
  • Identifying Open Ports: Discover which ports are accessible on servers, workstations, routers or other network devices. Open ports can represent potential entry points for attackers.
  • Reducing Attack Surface: Identify and close unnecessary open ports to reduce a system’s attack surface and improve its security posture.
  • Verifying Firewall Rules: Confirm that firewall rules are working as intended by checking whether specific ports are blocked or open as expected.
  • Detecting Unexpected Services: Spot services or applications listening on an open port that you didn’t expect, which may indicate unauthorised software.
  
  
• Network Troubleshooting and Diagnostics:
  • Verifying Service Availability: Check whether a specific service (a web server on 80/443, mail on 25/110/995, RDP on 3389, and so on) is actually listening and reachable on a given target.
  • Diagnosing Connectivity Issues: Work out whether a service is unreachable because its port is closed, blocked by a firewall, or the service isn’t running — use Ping First to see if the host responds at all.
  • Confirming Application Listening: Verify that an application you just deployed is correctly listening on its designated port, and use Banner Grab to confirm what is answering.
  
  
• System Administration and Configuration:
  • Mapping Network Services: Build an inventory of active services across devices by scanning a CIDR range and mapping open ports to common applications.
  • New Device Configuration: When setting up new servers or network devices, confirm that only the necessary ports are open and configured correctly.
  • Tracking Changes Over Time: Save a baseline and compare later scans to detect ports that have opened or closed since you last checked.
  
  
• Authorised Security Testing:
  • As a preliminary step in authorised security testing, identify potential entry points on a target by discovering open ports and the services running on them. (Only do this with explicit permission.)
  
  
• Home Network Management:
  • Check whether devices like network cameras, smart-home hubs or gaming consoles have ports unexpectedly open, and confirm that port-forwarding rules on your router are set up correctly.
  
  

Note: While port scanning is a fundamental network diagnostic and security tool, scanning networks or systems without explicit permission can be considered intrusive and may be illegal. Always ensure you have proper authorisation before scanning any IP address that is not your own or under your administration.