Network

Port Checker

Open Ports

Port scanner

Enter a domain or IP address and select ports to scan. Check port status and identify open ports for security analysis.

Enter comma-separated port numbers or use quick presets below

Quick presets:
Common
Web
Database
Security
Mail
Remote
Hosting

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Tool features

Comprehensive port scanning and network security analysis
4 checks

Port Scanning

Fast and accurate port status checking for any domain or IP address

Security Analysis

Identify open ports and potential security vulnerabilities

Fast Results

Concurrent port scanning for quick and efficient analysis

Service Detection

Automatic service name detection for common ports

What is a port scan & how it works

Mapping which services a host exposes

A port is a numbered endpoint a server uses to run a specific service — 80 and 443 for web traffic, 22 for SSH, 25 for mail, and so on. A port scan checks which of those ports are open (accepting connections), closed, or filtered, giving you a map of what a machine is exposing to the network.

This scanner tests the host and ports you choose from our servers and reports each port's status along with the service typically associated with it. It's useful for confirming a service is reachable, verifying a firewall change took effect, and spotting unexpectedly open ports that widen your attack surface.

Open port
A service is listening and accepting connections. Only expose the ports you actually need.
Closed vs filtered
Closed means nothing is listening; filtered means a firewall is silently dropping the probe.
Well-known ports
Ports 0–1023 are reserved for standard services (HTTP 80, HTTPS 443, SSH 22, SMTP 25).

How to use this tool

Scan a host's ports in four steps
1
Enter a domain or IP
Type the host to scan, for example example.com or 8.8.8.8.
2
Select the ports
Choose common ports or specify custom ones relevant to the services you're checking.
3
Run the scan
We probe each port from our servers and record whether it's open, closed, or filtered.
4
Review and secure
Confirm expected services are reachable and close any port that shouldn't be exposed.

Related tools

Keep debugging with tools from the same suite
4 tools
Online Ping
Ping servers to check connectivity and measure response time with detailed statistics
HTTP Status Checker
Check HTTP status codes and response details for any URL with detailed analysis
DNS Lookup
Perform DNS queries for A, AAAA, MX, TXT, CNAME, and other DNS record types
SSH Tunnel Helper
Generate SSH tunnel commands for secure port forwarding and proxy setup

Frequently asked questions

Common questions about port scanning
5 Q&A

An open port has a service actively listening and accepting connections. That's expected for services you run (like 443 for HTTPS) but a risk if the port shouldn't be exposed to the internet.

Closed means the host responded but nothing is listening on that port. Filtered means a firewall dropped the probe with no response, so the tool can't confirm whether a service is behind it.

Scanning hosts you own or have permission to test is fine and is standard security practice. Scanning systems you don't control may violate terms of service or law — only scan what you're authorised to.

Management and database ports exposed to the internet — like 22 (SSH), 3389 (RDP), 3306 (MySQL), or 6379 (Redis) — are common risks. Keep them firewalled or restricted to trusted IPs.

Ping (ICMP) and port checks are independent. A host can block ICMP while still accepting TCP connections on specific ports, so an open port with a failed ping is normal.