Uptime Basics monitors public HTTP and HTTPS endpoints. Destination checks protect the monitoring service and its customers while still supporting normal websites, APIs, paths, and query strings.
Supported targets
A monitor URL must:
- begin with
http://orhttps://; - use port 80 or 443, whether the port is written explicitly or implied by the scheme;
- resolve through public DNS to public IP addresses;
- remain within the URL length accepted by the monitor form;
- pass platform blocked-target and abuse-protection rules.
Full public paths and query strings are supported, such as https://example.com/health?mode=ready. A URL fragment beginning with # is browser-side information and is not part of the HTTP request.
Targets that are not allowed
Uptime Basics rejects:
localhostand local development names;- private, loopback, link-local, reserved, multicast, documentation, and other non-public IP ranges;
- destinations that resolve to a blocked non-public address;
- protocols other than HTTP and HTTPS;
- ports other than 80 and 443;
- URLs containing an embedded username or password;
- domains or URL patterns blocked for safety or abuse prevention.
The destination is checked during monitor creation and again during monitoring. Redirect destinations are validated before they are requested. This prevents a public hostname from being used to reach a private service after creation or through a redirect.
Monitoring a protected public endpoint
The endpoint must still be reachable from the public internet, but it can require supported non-interactive access settings. Use Basic authentication for HTTP Basic Authentication or Custom request headers for a dedicated allowlist or health-check value.
If a firewall, CDN, or bot-protection service rejects the request, configure a dedicated public health endpoint or allow the monitoring request through your own security controls. Uptime Basics does not bypass CAPTCHA, interactive login, browser JavaScript, or access restrictions.
If a valid public URL is rejected
Confirm the scheme and port, check public DNS from an independent network, and verify that every returned address is public. A newly changed DNS record may need time to propagate. Also check whether the URL redirects to a different host or unsupported port.
If the target is public and still cannot be added, contact Uptime Basics support with the URL and the exact validation message. Never include passwords, tokens, or private header values in a support message.