What is uptime monitoring?

Uptime monitoring is an external service that checks your site at intervals and tells you when it stops answering:

• External is the point - checking from outside your own network is what catches an outage you cannot see.
• Check more than the homepage - a working homepage with a broken checkout is still an outage.
• Alerts must reach a person - an email to an address nobody watches is not monitoring.
• Certificate expiry warnings are usually included, and catch a scheduled, avoidable outage.

Knowing before your customers tell you is the whole value. Free tiers cover a small business adequately.