Many free web-based DNS and domain name tools all in one location. Includes standard DNS lookups, WHOIS/IPWHOIS, and even obscure DNS hosting tests, IPv6, IP-to-country and spam database lookups. Fast and thorough.

Provides a free DNS report on your domain name, verifying that your DNS hosting is working properly. Includes over 40 different tests, looking for both minor and major problems.

Check the delegation of your domain. Has interesting graphical results.

Complete DNS traversal check. Shows every DNS server that is (or maybe) used for a DNS lookup.

DNSDig is a web version of dig. Allows queries for a domain's DNS from any machine on the Internet.

Online utility for DNS administrators. Test your DNS servers, domain registration, mail and web servers.

Handy web-based DNS lookup service, with links.

Web-based nslookup tool that lets you look up IP address information. Query their and other DNS domain name servers to look up and find IP address information of computers on the internet.

Provides basic forward and reverse DNS lookups, as well as MX record and server software lookups.

A WHOIS domain name search. Check domain name registrations, look up domain names, IP addresses, nameservers, registrars, etc.