Uptime monitoring
Whether your site answers at all.
Uptime is the foundational check — the one that earns its keep the loudest the first time it fires. A 502, a host suspension, a DNS record that drifted off the apex after a registrar migration, a CDN edge going dark during a scheduled rotation — every one of these shows up identically at the probe edge: the HTTP request timed out, or it returned a 5xx, or it never resolved. The probe does not care why. It just knows the site is not answering.
For a small business, the cost of an undetected outage is direct and immediate. A visitor hits the homepage during the two hours the site is down, sees nothing, and does not come back. Without a probe running from outside, the founder finds out when a customer emails to ask if the business is still open. With a probe, they get an email in the minute the probe fails — and a second short email when the site comes back up. The cost-lens on a four-hour order-wave outage — what twenty to forty missed orders during the loud order wave actually adds up to, and what shortens the lost-revenue window — is costed out in the dedicated breakdown on the website downtime cost for small business article.
The free uptime check runs the same probe against any URL, on demand, with no signup. The product runs it on a cadence — every five minutes on Starter, every minute on Pro — and alerts the moment the check fails. One URL, one email address, and the monitor watches every refresh in between. That is the entire surface area of uptime monitoring for a small-business site.