Free tools for website and domain health

Inspect a current signal, understand its limits, then monitor the signals that matter to your service.

Choose a check

Website health check — availability, DNS, TLS and email-domain findings
DNS Checker — Look up A, AAAA, CNAME, MX, NS and TXT records for a public domain.
SPF Checker — Inspect public SPF policy presence and detect multiple SPF records.
DMARC Checker — Inspect the public DMARC policy and aggregate-reporting configuration for an email domain.
DKIM Checker — Look up a DKIM public-key record using your domain and a selector supplied by your email provider.
SSL Certificate Checker — Check a public website certificate for trust, hostname matching, issuer and expiry.
Public Ping Test — Check public-host reachability, round-trip latency and packet loss with ICMP.
HTTP Status Checker — Check the HTTP response from a public URL and understand redirects, client errors and server failures.
Website Response Time Test — Measure DNS, connection, TLS, TTFB and HTML transfer timing for a public website request.
Redirect Checker — Follow a public URL through up to five redirects and inspect each HTTP status in the chain.
Security Headers Checker — Inspect common HTTP security response headers without scanning for vulnerabilities or exploiting a website.
Domain Expiry Checker — Look up domain registration expiry and registrar information where the registry publishes it through RDAP.
Cron Expression Checker — Validate a five-field cron expression and preview its next five run times in UTC without contacting a server.