Free online network tools for system administrators, developers, and IT professionals. Perform DNS lookups, check HTTP headers, verify SSL certificates, query WHOIS records, scan ports, and analyze network configurations — all from your browser without installing command-line utilities.
Key Features
- DNS Lookup — query A, AAAA, MX, CNAME, TXT, NS, and SOA records for any domain. Diagnose DNS propagation issues, verify email configuration, and check domain setup.
- HTTP Headers — inspect response headers returned by any URL, including caching directives, security headers, content types, and redirect chains.
- SSL Checker — verify SSL/TLS certificate validity, expiration dates, certificate chain, and cipher suites. Catch expiring certificates before they cause browser warnings.
- WHOIS Lookup — retrieve domain registration details including registrar, creation date, expiration date, and nameserver information for over 60 TLD extensions.
- My IP & IP Lookup — discover your public IP address instantly, or look up geolocation, ISP, and organization details for any IP address worldwide.
- Reverse DNS — find the hostname associated with any IP address through PTR record lookups, useful for email server verification and security analysis.
- Port Checker — scan specific TCP ports on any host to determine if they are open, closed, or filtered. Uses parallel non-blocking connections for fast results.
- Subnet Calculator — calculate network ranges, broadcast addresses, usable host counts, and wildcard masks from any CIDR notation or IP/subnet combination.
- User Agent Parser — decode any user agent string to identify the browser, operating system, device type, and rendering engine.
Who Uses These Tools
- System administrators troubleshooting DNS, SSL, and network connectivity issues across infrastructure.
- Web developers verifying HTTP headers, SSL configuration, and domain setup during deployments.
- Security analysts performing reconnaissance with WHOIS, reverse DNS, and port scanning.
- Network engineers calculating subnets and verifying routing configurations.
All network tools return real-time results from live queries. No installation or sign-up required — enter a domain or IP address and get instant diagnostics. Combine with our developer tools for a complete web development and operations toolkit.