5 free tools
Website Diagnostics
Check a website’s DNS records, HTTP and security headers, redirects and SSL certificate.
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DNS Lookup
Look up a domain’s DNS records: A, AAAA, CNAME, MX, NS, TXT, SOA, CAA, SRV and DMARC, or the name behind an IP address. -
HTTP Headers Checker
See the status code and every response header a web address returns, hop by hop, with timings and what each header does. -
Security Headers Checker
Check a site’s HTTPS and security headers (HSTS, Content-Security-Policy, X-Frame-Options and more) and its cookies, with advice on each. -
Redirect Checker
Trace every redirect from a web address to its final page: status codes, where each hop goes, loops and slow chains. -
SSL Certificate Checker
Check a server’s SSL/TLS certificate: who issued it, the names it covers, when it expires, the chain and the TLS version in use.