Website monitoring is the automated process of checking a site’s uptime, response time, and certificate or content health on a set schedule, so a problem surfaces as an alert instead of a customer complaint. A basic setup confirms the site responds. A complete one, like the Website Wizard in Nagios XI (sometimes called URL monitoring or site monitoring), also tracks how fast it responds and whether its SSL/TLS certificate is still valid.

Websites fail in specific, checkable ways: the server stops responding, a page starts returning 500s, a TLS certificate expires at 3 a.m. on a Saturday, or response time creeps up until the page effectively times out. Catching these as threshold breaches, not as user complaints, is the difference between a two-minute fix and a support queue full of cases.

The Website Wizard (Configure > Configuration Wizards > Website) sets up four checks in a few clicks:

• Availability. Confirms the site answers over HTTP or HTTPS and returns the status code you expect, not just that the port is open.
• Response time. Set Warning and Critical thresholds so a slow page alerts someone before users give up on it.
• SSL/TLS certificate expiration. Enter an https:// URL and an SSL Certificate check appears in Step 2. Set a “days to expiration” threshold and Nagios XI warns you ahead of expiry, not the day it happens. For certificates across many sites, see SSL Certificate Monitoring.
• Website content monitoring. Check that a specific string still appears on the page, so a page that loads but silently drops its content still trips an alert.

Two claims we’re not making, because they belong to separate Nagios solutions with their own licenses:

• Deep log analysis. The website checks in Nagios XI don’t parse server or application logs. That’s Nagios Log Server: centralized log collection, search, and alerting on log content. It’s a genuinely useful pairing with website monitoring, but it’s a separate solution, a separate install, and a separate license.
• Intrusion detection and threat scanning. Nagios XI doesn’t run malware or intrusion scans against your site. That capability, Suricata-based IDS/IPS alongside packet capture and Nmap scanning, lives in Nagios Network Analyzer, again a separate solution and license, not a feature of the Website Wizard.

If the goal is uptime and certificate alerts, XI alone covers it. If the goal is uptime, plus log-driven diagnosis, plus network-level threat detection, that’s three solutions with three licenses working together, worth scoping accurately before a purchase conversation, not after. Check out the Nagios Networking Toolkit for a bundled package of all three.

Website checks in Nagios XI sit next to your servers, network gear, and applications in the same status views, so this is one solution rather than another point tool bolted onto the stack. Nothing about it is a black box: you set the Warning and Critical numbers yourself, which means you always know exactly why an alert fired.

When the defaults aren’t enough, the check_ssl_cert community plugin, custom string matching, and additional wizards cover the cases the Website Wizard doesn’t.