Free Online Open Port Checker
Open Port Checker verifies whether specific TCP ports are accepting connections on any host or IP address. Five integrated tools live in one workspace: a single port tester, range scanner, common ports checker, bulk host processor, and a personal IP scanner. Just enter a hostname, pick your port, and results arrive within seconds. Each connection attempt captures latency alongside the status result, giving you both availability and performance data in a single check. Upload host lists from text files to process dozens of servers in one session, then download everything as CSV.
Port Check
Tests a single port on any host with instant open/closed results, service identification, and latency measurement.
Port Scanner
Scans up to 500 ports in a range to discover running services with parallel batch processing.
Common Ports
Checks 21 well-known service ports at once including HTTP, SSH, SMTP, MySQL, and more.
Bulk Check
Tests one port across multiple hosts with file upload support, live progress, and CSV export.
My Ports
Detects your public IP and scans common ports to reveal your network exposure and verify firewall rules.
Online Open Port Checker for Server Monitoring and Network Diagnostics
Knowing which ports are open on a server is critical for troubleshooting connectivity issues, validating deployments, and maintaining security posture. Once you enter a hostname, the tool initiates a TCP connection attempt to each specified port and reports whether the handshake completed successfully. Open ports indicate active listeners, while closed results mean either no service is bound or a firewall is blocking access. The response latency for each port gives you a snapshot of network performance between your location and the target server.
TCP Connection Testing with Latency Measurement
Every port check measures the time for a complete TCP three-way handshake. This round-trip latency helps identify not just whether a port is reachable, but how responsive the service behind it is. High latency values can indicate network congestion, geographic distance, or an overloaded server, all useful signals when diagnosing connectivity problems.
Service Identification for Common Ports
Results automatically include service names for well-known port numbers. Port 22 shows as SSH, 80 as HTTP, 443 as HTTPS, 3306 as MySQL, and so on. This instant identification saves you from cross-referencing port numbers manually and makes scan results immediately actionable for teams reviewing server configurations.
Scan Port Ranges, Common Services, and Bulk Host Lists
A single port check only tells part of the story. The port scanner lets you sweep a range of up to 500 ports at once, revealing which services are exposed across a wider attack surface. Under the hood, ten ports run in parallel so results build quickly and update live as each batch finishes. If you already know which services to look for, the common ports checker handles 21 well-known ports in one click, organized into categories like web, email, remote access, and databases.
Bulk Host Processing with File Upload
Managing multiple servers means checking ports across many hosts. Paste your hostnames into the text area or upload a .txt file with one host per line. Each host is processed sequentially with a live progress bar that updates as results come in. Cancel mid-run if needed, and download the collected data as CSV. Any line prefixed with # is skipped as a comment, so you can annotate your host lists without reformatting them.
Check Your Own Public IP for Exposed Services
The My Ports tool auto-detects your public IP address and scans all common service ports against it. This reveals which services on your network are visible from the outside, helping you verify that your router and firewall are configured correctly. Security tips alongside the results guide you toward hardening any unintentionally exposed ports.
Free Open Port Checker for Developers and System Administrators
Whether you are deploying a new application, auditing firewall rules, or debugging why a client cannot reach your API, port checking is a fundamental network diagnostic step. Every feature works instantly with no account creation, no rate limits, and no hidden restrictions. Export results as CSV for documentation, incident reports, or compliance audits. All port checks run server-side through a lightweight proxy, so results reflect real external connectivity rather than local network conditions.
No Signup, No Limits, Instant Results
Every tool in the workspace is available immediately. Check single ports, scan ranges, test common services, process bulk lists, and scan your own IP without creating an account or waiting for credits. Results include full connection details, service identification, and latency data, all exportable as CSV.
Server-Side Port Testing for Accurate Results
Port checks execute on the server rather than in your browser, which means results accurately reflect external accessibility. If you need to verify that a port is reachable from the public internet rather than just your local network, this architecture gives you the ground truth you need for deployment validation and security audits.
Related Network and Server Tools
If you work with servers and networking regularly, these tools complement what you can do here:
- Port Scanner -- scan a range of ports to discover running services
- Common Port Checker -- check 21 well-known service ports in one click
- Bulk Port Checker -- test a port across multiple hosts with file upload
- My Open Ports Scanner -- check your own public IP for exposed services
- DNS Lookup -- query A, AAAA, CNAME, MX, TXT, and other DNS record types
- WHOIS Lookup -- check domain registration data, age, and expiry
- IP Lookup -- geolocate IP addresses and find ISP information
