SiteCheckTools

SiteCheckTools is nine free web tools in one place, made for the people who keep websites running. Check DNS records across four public resolvers, read an SSL certificate chain and its expiry date, look up a domain's registrar over RDAP or an IP's owner, follow a redirect chain hop by hop, test whether a site is down from several regions, and measure Core Web Vitals alongside server response time. It also has a WordPress theme detector and a domain name generator.

Every result explains what the value is and what it should be. If a lookup cannot be completed, the tool reports the failure rather than a guess. No sign-up.