Website availability checker
Confirm quickly whether a page is reachable from outside your own network, see the HTTP status and response time, and spot redirect or certificate problems before users report them.
How it measures
- We send one GET request from a single probe location with a 10-second deadline and follow up to five redirects, validating every destination.
- Timing is server-side request latency: DNS resolution, TCP connect, TLS handshake, time to first byte and download of at most 128 KiB.
- TLS certificates are validated against public roots; a failed validation is reported as a failure, never hidden.
Limits
- One successful observation from one location is not proof that the site is up for every visitor worldwide.
- Request timing is not browser rendering performance and says nothing about Core Web Vitals.
- Only public hostnames on standard web ports are checked. Private networks and cloud metadata addresses are refused.
Troubleshooting
- Status 5xx
- The server accepted the connection but failed to produce a response. Check application logs, upstream dependencies and recent deployments.
- Connection timed out
- Nothing answered within the connect deadline. Check firewalls, load balancers and whether the host resolves to the right address.
- TLS certificate error
- The certificate is expired, does not match the hostname or is not trusted. Renew or reissue it and verify the full chain is served.