All tools

Website Health Check

Run the main website, DNS and email checks on one site at once and get a short report, area by area, with links to the full results.

Website Down Checker

Check whether a website is responding right now, from our server: status, response time, redirects, IP addresses and HTTPS.

SSL Certificate Checker

Check whether a site's HTTPS certificate is valid and trusted, which names it covers, and when it expires.

HTTP Header Checker

See the HTTP status and every response header a website sends, for the final page and each redirect on the way.

Security Header Checker

Check which browser security headers a website sends (HSTS, CSP, X-Content-Type-Options, Referrer-Policy and Permissions-Policy) and what they do.

Redirect Checker

Follow a web address through every redirect, with the status code, destination and timing of each hop.

Robots.txt Checker

See a site's robots.txt rules for each crawler, spot mistakes, and test whether a page may be crawled.

Sitemap Checker

Find a site's XML sitemap, count its addresses and spot problems that make search engines ignore entries.

DNS Lookup

Look up the DNS records published for a domain, one type or all common types at once, or the reverse DNS name of an IP address.

MX Lookup

See which mail servers receive email for a domain, in priority order, with each server's addresses.

CAA Checker

See which certificate authorities a domain allows to issue its certificates.

DNSSEC Checker

Check whether a domain is signed with DNSSEC and whether validating resolvers accept it.

SPF Checker

Check that a domain's SPF record is valid, stays within the 10-lookup limit, and says what you expect about servers that may send its mail.

DMARC Checker

Find the DMARC policy that applies to a domain, see what each setting means, and spot mistakes that make receivers ignore it.

BIMI Checker

Check whether a domain is set up to show its logo next to its emails: the BIMI record, DMARC, the logo file and the mark certificate.

MTA-STS Checker

Check whether a domain asks other mail servers to use secure, verified connections when they deliver its email.

TLS-RPT Checker

Check where other mail servers send reports when they can't make a secure connection to a domain's mail servers.

What Is My IP

Your public IP address as websites see it, plus what your browser shares with every site you visit.

IP Lookup

See which network an IP address belongs to, its approximate country, and its reverse DNS name.

Reverse DNS

Find the host name for an IP address, and check that the name points back to it.