$ curl -I
HTTP headers checker
Fetch a URL and inspect every response header — with a security audit of HSTS, CSP, and the other headers your site really should be sending.
Try: · ·
Missing security headers?
LightningByrd hosting ships with sensible security headers configured by default. Our team can also audit and harden your existing setup.
Get a security audit →More free tools
All tools →Domain availability checker
See if a domain is available, who registered it, when it expires, and what nameservers it uses.
SSL certificate checker
Inspect any site's SSL/TLS certificate — issuer, validity dates, SANs, and chain length.
DNS lookup
Pull A, AAAA, MX, TXT, NS, CNAME, and SOA records for any domain.