Free tools
Check a site in seconds
Eight quick checks for any public site. No account needed. Each runs once from Cloudflare's edge and says plainly what one check can't tell you.
- Website uptime checkerIs it up? Status, time and every redirect.Open
- API endpoint checkerStatus, JSON and CORS for GET or HEAD.Open
- HTTPS checkerValid certificate, HTTP to HTTPS redirect, HSTS and preload.Open
- Security headers checkerAn A+ to F grade and a fix for each header.Open
- Agent readiness checkerllms.txt, AI crawler rules, agent card and bot blocks.Open
- DNS lookupA, AAAA, CNAME, MX, TXT, NS, CAA and DNSSEC.Open
- Social preview checkerOpen Graph and X/Twitter tags, and whether the image loads.Open
- Domain expiry checkerExpiry date and registrar from RDAP, where the registry publishes it.Open
The checks are made by SupercheckBot. What it does and how to opt out