How to Monitor Website Uptime Independently of Your Hosting Provider

Decide what “up” means

Choose the reader's critical task: load the site, sign in, or retrieve an order. Start with a public HTTPS check, then add an assertion for content that actually represents the page. A home page cached at the CDN may remain available while checkout is broken.

Use a separate synthetic account or test flow for authenticated functionality. Avoid real purchases, customer emails or irreversible changes. If a journey cannot safely run unattended, document the narrower coverage instead of labeling an HTTP check an end-to-end test.

Create the measurement record

Those numbers are an example, not recommended defaults for every service. Blackbox exporter (opens in a new tab) supports probes that can provide input to this kind of measurement. Regardless of implementation, monitor the probe's own collection path too: absent measurements must not silently count as success.

Keep observations separate from notifications

Store each failed observation even if your paging rule waits for repeated failures. Otherwise the uptime report can lose the very failures the notification policy chose to debounce.

For a simple observation ratio, divide successful valid checks by all valid checks in the reporting window. Label it “successful checks,” not exact elapsed uptime. Report missing samples separately. To estimate duration, document how you place boundaries between the last success and first failure, and between the last failure and next success.

A brief outage entirely between two samples can be invisible. Increasing frequency changes detection resolution; it does not turn an observation system into perfect knowledge.

Test three misleading states

On a test site, return an error response, keep HTTP 200 but remove the expected marker, and delay the response beyond the timeout. Each should produce its intended failure classification. Then make the test endpoint healthy and confirm both recovery and the retained failure history.

If the host is multi-region, record results by probe location. A single location cannot substantiate a global availability claim, and disagreement between two locations warrants diagnosis rather than automatically declaring either result false.

Compare like with like

Collect your UTC window, target, raw failures, missing observations and method before discussing a discrepancy with a host. Ask what their availability figure covers: infrastructure, network, a particular endpoint or something else. Read the actual service agreement for exclusions rather than assuming your measured downtime is credit-eligible.

The useful result is a reproducible account of what clients could observe, with enough detail to locate the fault. For the next incident, link the probe and its owner from the runbook.