Uptime, SSL and domain expiry monitoring for all your websites

Websites rarely die dramatically. They go down at 3 a.m. after a hosting update, show a browser warning because a certificate didn't renew, or disappear because a domain expired on a credit card that no longer exists. All of these are detectable, most of them weeks in advance. This guide covers what to monitor, how often, and how to set up alerts you will actually trust.

The four things that take a site offline#

The first one needs frequent checks. The other three need early warnings, and they are the ones people usually forget.

How often to check#

• Every 1 minute for shops and sites where an hour offline costs real money.
• Every 5 minutes for business sites and important landing pages.
• Every 15 minutes for blogs, portfolios and side projects.

More frequent checks find outages sooner, but they also find more blips. That's why confirmation matters more than frequency.

Avoiding false alarms#

An alert you learn to ignore is worse than no alert. Good monitoring:

• Confirms before alerting: a single failed check, a timeout from a slow host, isn't an incident. Re-check before declaring the site down.
• Doesn't flap: one "down" and one "recovered" message per incident, not ten.
• Keeps incident history with duration, so you can show a client (or a host) the real uptime percentage.

SSL certificates are getting shorter#

Public TLS certificates now have a much shorter maximum lifetime than a few years ago: the CA/Browser Forum cut it to 200 days in March 2026, and it is scheduled to keep falling to 47 days by 2029. Many sites already use 90-day certificates from Let's Encrypt. Shorter lifetimes mean more renewals, and more chances for one to fail silently. Get warned at least 14 days before any certificate expires.

Domain expiry#

Domain expiry dates are public through RDAP (the successor of WHOIS). Check them monthly and warn 30–60 days ahead. For client sites, also note who owns the registrar account: the most common reason a domain expires is that the renewal email goes to someone who left.

robots.txt and sitemap changes#

A single line in robots.txt (Disallow: /) can remove a site from Google in days. Watch both files for changes and get alerted when they change, especially after deploys and migrations.

Monitoring all your sites in one place#

byanalytics checks every site's availability (every 15 minutes on Free, 5 on Pro, every minute on Business), confirms failures before raising an incident so you don't get flapping alerts, keeps incident history and uptime percentages, warns before SSL certificates and domains expire, and watches robots.txt and the sitemap for changes. It all appears next to traffic, search data and Core Web Vitals, and in the monthly client report. See plans or the full setup in How to monitor multiple websites from one dashboard.

FAQ#

How often should I monitor website uptime?#

Every minute for shops and revenue-critical sites, every 5 minutes for business sites and every 15 minutes for blogs and side projects, always confirming a failure before alerting.

How do I get notified before my SSL certificate expires?#

Use a monitor that reads the certificate's expiry date on every check and alerts you at least 14 days before it expires, since automatic renewals can fail silently.

How can I check when a domain expires?#

Query RDAP, the modern replacement for WHOIS, or use a monitoring tool that does it for you and warns 30 to 60 days before the expiry date.

What uptime percentage is good?#

99.9 % allows about 43 minutes of downtime a month; 99.5 % allows about 3.6 hours. Most small sites on decent hosting can stay above 99.9 %.