SiteState tool cluster
Website health tools
Run live diagnostics for availability, HTTPS, DNS, HTTP responses, redirects and server timing. These tools answer current-state questions quickly, while SiteState monitoring adds history, incidents and regression context.
website uptime checker · is my website down
Website Uptime Checker
Check whether a public website is responding right now and inspect HTTP status and timing.
Open free toolssl checker · ssl certificate test
SSL Checker
Check HTTPS, browser-visible certificate validity, TLS protocol, issuer and expiry details.
Open free toolsecurity headers checker · hsts csp
Security Headers Checker
Check six common browser-facing security headers and see which baseline headers are missing.
Open free toolcheck website redirects · check site redirects · redirect checker
Redirect Checker
See redirect count, final destination URL, final status and browser timing context.
Open free tooldns checker · dns lookup
DNS Checker
Look up A, AAAA, CNAME, MX, NS and TXT records for the public website hostname.
Open free toolhttp status code checker · url status
HTTP Status Code Checker
Check the final HTTP status, final URL, redirect count and response timing.
Open free toolhttp headers checker · response headers
HTTP Headers Checker
Inspect sanitized public response headers from the final main document.
Open free toolwebsite response time test · server timing
Website Response Time Test
Break response time into DNS lookup, connection, TLS, TTFB and page-load timing.
Open free toolFrom one-off check to continuous state
Website monitoring
Use the free tools for point-in-time diagnosis. When the website matters continuously, move the same site into SiteState monitoring so changes, incidents and regressions build a useful history.
Explore website monitoring