Free tools
Quick checks for any website
A set of free, single-purpose tools for uptime, security, performance, DNS, and email — no account needed.
UptimeWebsite Status CheckerCheck if a website is up right now.SecuritySSL Certificate CheckerInspect a site’s SSL/TLS certificate and expiry.DNSDNS LookupLook up the DNS records for any domain.SecurityHTTP Security Headers CheckerSee which security headers a site sends.PerformancePage Speed TestMeasure load time and Core Web Vitals.DomainsDomain & WHOIS LookupSee a domain’s registration and expiry.SEORedirect CheckerTrace the full redirect chain of a URL.EmailEmail Deliverability CheckerCheck SPF, DKIM, and DMARC for a domain.SEOSitemap & Robots CheckerCheck robots.txt and the XML sitemap.
Stop finding out from your customers.
Set up your first monitor in minutes and let SentinelWeb keep watch.