Free Port Checker Online - Check Open Ports (TCP & UDP Ports)
Simply leverage our port checker, designed to identify open and closed ports. It combines traditional TCP and UDP scanning techniques to ensure 100% accurate results. This helps you understand your network's connectivity status and flag potential vulnerabilities.
Think of our Port Checker as a highly advanced investigator for your computer's front doors – the ports. It's like having a super-smart assistant that goes door-to-door — checking if each door (port) is open, closed, or even locked.
You can ask our tool which types of ports to check. You need to check only specific ports you're concerned about, like ports used for gaming, applications, or sharing files. Or, probably, you’re required to scan the common ports that are often used. Just a couple of clicks, and our port checker online will have you all covered!
What Is a Port Scanner (Port Tester)?
According to the SANS Institute, port scanning is one of the most popular techniques hackers use to discover vulnerabilities and exploit services to break into systems.
A port scanner is a network scanner that quickly finds the open ports on a computer network. The open port check tool displays which port on a network are available to communicate.
How Does an Open Port Checker Tool Work?
A scan port online tool sends a TCP or UDP network packet to ask about the port's current status (check port). The three types of responses that it will get are
- Open/Accepted: The port is available to receive the traffic.
- Closed/Not Listening: The port is currently in use and not open to receive the traffic.
- Filtered/Dropped/Blocked: The port blocked all kinds of traffic and did not even bother to respond.
How to Use Our Port Checker?
Our Port checker boasts a powerful yet intuitive user interface, making scanning any port easier. Access our port checker and then follow this method to perform a quick port test:
Enter Domain/IP
Specify the domain name or IP Address in the search bar whose ports you must check.
Select Port Type
Our tool will automatically select the “Custom Ports” when you access it. You must manually enter each port number you’d like to scan.
Select any of the following ports to check if you do not remember the port numbers. No matter which type you choose, our tool will fetch and display all the associated port numbers immediately.
- Server Ports
- Game Ports
- Application Ports
- P2P Ports
Enhancing your experience, our port checker also provides a complete list of Common Ports. It lets you click on any port number or scan all common ports in one attempt.
Start Port Scanning
Click on “Check” to run our online port checker. It will quickly test each port and display the results.
It will display “Open” next to each port that receives traffic. If it shows “Timedout,” it will indicate that the respective port is unavailable or blocked.
How to Obtain Your Port Number?
To access various sites and servers online, you may need to find your server's port numbers. Follow the steps below based on your computer's operating system.
For Windows:
- Open the Command Prompt.
- Enter the command "ipconfig".
- Execute the command "netstat -a" to view a list of all port numbers.
For Mac:
- Access System Preferences.
- Navigate to the "Network" section.
- Click on "Advanced."
- Select the "Port Scan" tab to find the port numbers.
What if I Encounter Errors or Issues During Scanning?
If you experience problems, ensure you've entered the correct domain/IP and that your internet connection is stable. If issues persist, contact us for assistance.
Benefits of Using Our Port Checker Tool
Here are some common scenarios where you might use the Port Checker Tool:
Testing Port Availability:
The open port scanner checks if a specific port is open and accessible on a target system. For example, if you want to see if a web server is reachable, you would check if port 80 (HTTP) or port 443 (HTTPS) is open.
Troubleshooting Connectivity Issues:
When you encounter connection problems with an application or service, the Port tester can help determine if the issue lies with a blocked or closed port. If a firewall or router blocks a port, the service relying on that port will not function correctly.
Security Assessment:
As a network administrator or security professional, you can use the tool to check open ports to assess the security of your network. You can identify potential vulnerabilities and take appropriate actions to secure your network by checking for open ports that are not required for essential services.
Verifying Port Forwarding:
Suppose you have set up port forwarding on your router to allow external access to a specific service on your local network (e.g., running a web server or hosting a game). In that case, our port forwarding test tool can verify if the forwarding is configured correctly and if the service is reachable from outside your network.
Debugging Server Configuration:
When setting up a server for a specific service, such as email, FTP, or database, you can use the port scanner to verify that the required ports are open and correctly configured.
Testing Firewall Rules:
Network administrators can use the online port scanner to ensure firewall rules are properly configured and do not accidentally block necessary communication.
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Which Are the Most Scanned Ports?
According to the Nmap database, the topmost scanned ports are
- 20 & 21 - FTP (File Transfer Protocol)
- 22 - SSH (Secure Shell)
- 23 - Telnet, a Remote Login Service
- 25 - SMTP (Simple Mail Transfer Protocol)
- 53 - DNS (Domain Name System)
- 80 - HTTP (Hypertext Transfer Protocol)
- 110 - POP3 (Post Office Protocol 3)
- 111 - Rpcbind
- 135 - MSRPC (Microsoft Remote Procedure Call)
- 139 - NetBIOS-SSN
- 143 - IMAP (Internet Message Access Protocol)
- 443 - SSL / HTTPS (Hypertext Transfer Protocol Secure)
- 445 - Microsoft-DS
- 502 - Modbus Protocol
- 587 - SMTP (Simple Mail Transfer Protocol)
- 993 - IMAPS (Internet Message Access Protocol over SSL)
- 995 - POP3S (Post Office Protocol 3 over SSL)
- 1723 - PPTP (Point-to-Point Tunneling Protocol)
- 2525 - Simple Mail Transfer Protocol (SMTP) Alternate
- 3306 - MySQL
- 3389 - MS WBT Server
- 5900 - VNC
- 8080 - HTTP-Proxy
Note: The IANA maintains the complete list of the port numbers and protocols assigned to them.
Frequently Asked Questions
In case you have got any questions on your mind regarding Ports and Port Scanning, then here’s everything you need to know.
What are ports in networking?
In networking, a port is like a designated entrance on a computer or device where data can flow in or out. It's a way for different applications and services to communicate with each other over a network.
Ports facilitate computers to differentiate among different kinds of traffic. The email traffic lands on a different port (port 25), and web traffic lands on a different (port 80) even though both reach the computer over the same network connection.
The incoming packet's headers define which port it should be forwarded to. Each network request contains the port, IP address, and protocol to complete the request's destination network address.
There are two types of network ports on each computer.
- TCP (Transmission Control Protocol) ports
- UDP (User Datagram Protocol) ports
What is the difference between TCP and UDP ports?
TCP ports are used for reliable, ordered, and error-checked communication between applications. At the same time, UDP ports offer faster but less reliable communication, making them suitable for tasks where speed is more important than accuracy.
How many ports does a computer have?
Typically, a computer can have thousands of ports, but they are organized into two main categories: TCP (Transmission Control Protocol) ports and UDP (User Datagram Protocol) ports. Each category has its own range of port numbers.
What is port forwarding/mapping?
Port forwarding is a useful technique that allows external devices or networks to access specific ports on a local network, typically within a home router. It's usually used to enable remote access to devices like security cameras or game consoles.
What are custom ports?
Custom Ports allow the users to specify individual port numbers for scanning manually. This option is useful when you have specific ports you want to check.
How do I know if ports 80 and 443 are open?
You can simply leverage our tool. Select the port type “custom ports” and type “443,80” in the port section. Click the “Check” button to let our port scanner run and check which port is open or closed.
Is it OK to leave port 80 open?
Port 80 doesn't inherently pose a security threat. Nevertheless, if it remains accessible without proper configurations, malicious actors can exploit it to breach your systems and access data. Unlike the encrypted port 443 (HTTPS), port 80 lacks encryption, rendering it susceptible to cybercriminals who can readily infiltrate, expose, and manipulate sensitive information.
Are open ports a security risk?
Yes. Open ports can be a security risk if they are not properly secured. Hackers might exploit open ports to gain unauthorized access to a network or device. Monitoring and securing open ports to maintain network security regularly is important.
How can I secure open ports on my network?
Here are a few steps to follow to secure open ports on your network or device:
- Leverage a firewall to filter incoming and outgoing traffic.
- Regularly update and patch software to prevent vulnerabilities.
- Implement strong access controls and authentication mechanisms.
- Close unnecessary ports that are not actively used.
Can I close the ports on my computer?
Yes. You can close ports on your computer to limit external access. This is usually done through firewall settings or network configuration. It is important to know that closed ports help to reduce the potential attack surface for malicious actors.
Does our Port Checker tool help you identify if a port is misconfigured?
Yes, our Port Checker tool helps you identify if the port is misconfigured. Like, if some port is already open and accessible but shown as closed it seems that it is misconfigured.
Does our Port Checker detect if a port is temporarily unavailable?
The port checker online detects if the port is open or not. This also helps the user to identify if the port is facing some issue or is temporarily unavailable.
