About NetProbe

Free DNS and network tools that run in your browser, with no sign-up.

NetProbe is an independent project that puts the checks network administrators, developers and website owners run every day on one site. Each tool has its own page, explains how to read its result and answers the usual questions about it.

What you can do here

• Check DNS propagation across many public resolvers, or look up a single MX, NS or CNAME record.
• Look up a domain with WHOIS, check whether a name is available, or find the IP address of a domain.
• Find your public IP address, look up any IP address, test an open port or see whether an IP is on a spam blocklist.
• Validate email authentication with the SPF, DKIM and DMARC checkers.
• Work out a subnet, identify a device vendor from its MAC address, or compare public DNS servers.

Where the data comes from

NetProbe does not keep its own copy of the internet. Each result is fetched live from the source that owns the data: public DNS resolvers for DNS records, the domain registries' RDAP services for registration data, IP geolocation providers for locations, DNS blocklists for spam listings, and the IEEE registry for MAC address vendors. Because the data comes from third parties, a result can differ from what you see on your own network, and IP locations are estimates.

How it is paid for

The tools are free to use. The site may show advertising and uses privacy-conscious analytics to see which tools are used. The privacy policy explains exactly what is collected.

Limits

To keep the tools from being used against other people's servers, private addresses are blocked, only common ports can be tested, and each visitor has a rate limit. Results are provided as is, without any guarantee, so confirm important changes with your DNS host or registrar. Found a wrong result? Please get in touch.