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What to Look for in a WordPress Site Monitoring Tool

WordPress powers over 40% of all websites on the internet.

That's a lot of sites. And a lot of things that can go wrong.

If you run a WordPress site, you already know the feeling. You wake up, check your email, and find angry messages from customers saying your site has been down for hours.

Or worse. Your site shows a database error to every visitor while your cache serves a perfect-looking page to monitoring tools.

Generic monitoring tools miss WordPress-specific issues all the time. They check if your server responds with 200 OK and call it a day. Meanwhile, your actual site is showing "Error establishing a database connection" to everyone.

This guide shows you exactly what to look for in a WordPress monitoring tool.

The Cache Problem: Why Most Monitoring Fails for WordPress

Here's something most WordPress site owners don't realize.

Your caching plugin is hiding your problems.

When a monitoring tool checks your site, it often gets a cached version. The cache serves a perfect-looking page while your actual site is broken behind it.

Your database could be down. Your PHP could be throwing fatal errors. But the monitoring tool sees the cached page and reports everything is fine.

This is why cache-bypass monitoring is the single most important feature for WordPress sites.

How Cache-Bypass Monitoring Works

The solution is simple. Add a URL parameter that tells your cache to skip serving the cached version.

Instead of monitoring yoursite.com, you monitor yoursite.com/?site_check=1.

Most caching plugins can be configured to bypass cache when this parameter is present. WP Super Cache, W3 Total Cache, WP Rocket, and LiteSpeed Cache all support this.

How to set it up:

  • Add a cache exclusion rule for URLs containing site_check=1
  • Configure your monitoring tool to check yoursite.com/?site_check=1
  • Now every check hits your actual server, not the cache

Note: Your caching plugin should skip the cache when you pass the ?site_check=1 parameter. If you notice it keeps serving the cached page, check your caching plugin settings to exclude that parameter from cache.

This one change transforms your monitoring from useless to useful.

Without it, you could have hours of downtime while your monitoring reports 100% uptime. With it, you catch problems the moment they happen.

WordPress Error Keywords You Must Monitor

WordPress has specific error messages that appear when things break.

A good monitoring tool should scan your page content for these keywords and alert you immediately when they appear.

Critical Error Keywords to Monitor

Database errors:

  • "Error establishing a database connection"
  • "WordPress database error"
  • "Table doesn't exist"

PHP errors:

  • "Fatal error"
  • "Parse error"
  • "Syntax error"
  • "Warning:"
  • "Notice:"

Resource limits:

  • "Allowed memory size exhausted"
  • "Maximum execution time exceeded"
  • "Out of memory"

WordPress-specific errors:

  • "There has been a critical error on this website"
  • "Briefly unavailable for scheduled maintenance"
  • "This site is experiencing technical difficulties"

Server errors:

  • "500 Internal Server Error"
  • "503 Service Unavailable"
  • "504 Gateway Timeout"

Why Keyword Monitoring Matters

Your site can return a 200 OK status code while displaying an error message.

This happens all the time with WordPress. The server responds successfully, but the page content shows "Error establishing a database connection" in big letters.

Without keyword monitoring, your monitoring tool thinks everything is fine. With keyword monitoring, you get an instant alert.

Pro tip: Also monitor for the absence of expected keywords. If your homepage should always contain "Welcome" or your company name, set up an alert when that text is missing. This catches blank pages and severe layout breaks.

PHP Error Monitoring: Notices, Warnings, and Fatal Errors

PHP errors are the silent killers of WordPress sites.

Many WordPress sites run with PHP error display enabled. When something goes wrong, these errors appear right on the page for everyone to see. Your visitors see ugly error messages. Your site looks broken and unprofessional.

A good monitoring tool catches these before your customers do.

Types of PHP Errors to Monitor

Fatal Errors (Critical)

Fatal errors stop PHP execution completely. The page breaks.

Keywords to monitor:

  • "Fatal error:"
  • "Fatal error: Uncaught"
  • "Fatal error: Allowed memory size"
  • "PHP Fatal error"

These need immediate attention. Your site is broken.

Parse Errors (Critical)

Parse errors mean PHP can't understand your code. Usually caused by syntax mistakes after editing files or bad plugin updates.

Keywords to monitor:

  • "Parse error:"
  • "Parse error: syntax error"
  • "PHP Parse error"

Warnings (Important)

Warnings don't stop execution, but they indicate something is wrong. They often appear before bigger problems.

Keywords to monitor:

  • "Warning:"
  • "PHP Warning"

Notices (Low Priority)

Notices are informational. They point to potential issues but don't break functionality.

Keywords to monitor:

  • "Notice:"
  • "PHP Notice"

Why PHP Errors Matter for Monitoring

Even if error display is turned off in production, some errors still leak through.

Plugin conflicts, theme issues, and PHP version mismatches all cause errors. These errors might appear on specific pages, during certain actions, or only under load.

Your monitoring tool should catch:

  • Fatal errors that break pages completely
  • Warnings that indicate deteriorating health
  • Any PHP error text visible on the page

The WP_DEBUG Problem

Many developers leave WP_DEBUG enabled accidentally. When this happens, every PHP notice and warning shows on the live site.

Monitor for these keywords to catch WP_DEBUG leaks:

  • "Notice: Undefined variable"
  • "Notice: Undefined index"
  • "Deprecated:"
  • "Warning: Cannot modify header"

HTTP Status Code Monitoring

Your monitoring tool must check HTTP status codes, not just whether the page loads.

A page can return content while signaling an error through its status code. Your monitoring should catch any status code above 201.

Status Codes That Signal Problems

Success codes (no alert needed):

  • 200 OK - Everything is fine
  • 201 Created - Resource created successfully

Redirect codes (usually fine, but monitor):

  • 301 Moved Permanently - Permanent redirect
  • 302 Found - Temporary redirect
  • 304 Not Modified - Cache validation

Client error codes (investigate):

  • 400 Bad Request - Malformed request
  • 401 Unauthorized - Authentication required
  • 403 Forbidden - Access denied
  • 404 Not Found - Page doesn't exist
  • 429 Too Many Requests - Rate limited

Server error codes (critical):

  • 500 Internal Server Error - Something broke
  • 502 Bad Gateway - Server communication failed
  • 503 Service Unavailable - Server overloaded
  • 504 Gateway Timeout - Server took too long

Why Status Codes Matter

Your site might return a 500 error with a custom error page that looks almost normal.

Without status code monitoring, your tool might see the error page content and think everything is fine. With status code monitoring, you get an alert immediately.

Best practice: Alert on any status code above 201 for critical pages. For login pages and admin areas, 302 redirects are expected. Configure your monitoring to understand the difference.

Common HTTP Status Code Issues in WordPress

503 Service Unavailable during updates:
WordPress briefly returns 503 during core, plugin, or theme updates. If this persists, the update failed.

500 Internal Server Error from plugin conflicts:
A bad plugin update often causes 500 errors on specific pages or site-wide.

403 Forbidden from security plugins:
Security plugins can accidentally block legitimate requests, returning 403 errors.

504 Gateway Timeout from slow PHP:
Heavy database queries or slow plugins can cause timeouts, resulting in 504 errors.

404 Not Found from permalink issues:
Broken permalinks, deleted pages, or misconfigured .htaccess can cause 404 errors on pages that should exist.

Critical WordPress Pages to Monitor

Your homepage isn't the only page that matters.

Different parts of WordPress can fail independently. Your homepage might work while wp-admin is completely broken. Or your checkout page might be down while everything else looks fine.

Essential Pages to Monitor

Homepage with cache bypass:

https://yoursite.com/?site_check=1

Your main entry point. Monitor with cache bypass enabled.

WordPress login:

https://yoursite.com/wp-login.php

If users can't log in, they can't access their accounts. For membership sites and WooCommerce stores, this is critical.

Admin dashboard:

https://yoursite.com/wp-admin/

You'll get a redirect if not logged in, but a working redirect (302) is better than a 500 error.

REST API:

https://yoursite.com/wp-json/

Many plugins and the block editor depend on the REST API. If it's broken, large parts of WordPress stop working.

WooCommerce checkout (if applicable):

https://yoursite.com/checkout/

The most important page for e-commerce. A broken checkout page means zero sales.

Contact forms:
If your contact form is on a dedicated page, monitor it. A broken contact form loses leads silently.

How Many Monitors Do You Need?

At minimum, monitor your homepage with cache bypass.

For business sites, add wp-login and your most important conversion pages.

For WooCommerce stores, add the shop page, cart, and checkout.

For membership sites, add the login page and member dashboard.

SSL Certificate Monitoring for WordPress

SSL issues are especially common on WordPress sites.

WordPress sites often have mixed content problems after migrating to HTTPS. Plugins and themes can inject HTTP resources. And SSL certificates expire just like on any other site.

What to Monitor

Certificate expiration:
Set alerts for 30, 14, and 7 days before expiration. This gives you time to renew without panic.

Mixed content:
Your site might load fine, but browsers show a warning because some images or scripts load over HTTP instead of HTTPS.

Redirect chain:
Your site should redirect HTTP to HTTPS cleanly. Multiple redirects slow things down and can cause issues.

Certificate validity:
A misconfigured certificate can make your site show security warnings to visitors.

Common WordPress SSL Problems

  • Old image URLs still pointing to HTTP
  • Plugins injecting HTTP resources
  • Theme files with hardcoded HTTP links
  • CDN misconfiguration serving HTTP content
  • SSL certificate not covering www subdomain

A monitoring tool that checks SSL status saves you from these embarrassing issues reaching your visitors.

WordPress Performance Monitoring

WordPress sites can be slow. You know this.

But there's a difference between "a bit slow" and "something is wrong" slow.

Performance monitoring catches degradation before it becomes downtime.

What to Monitor

Response time:
Track how long your server takes to respond. If your normal response time is 500ms and it suddenly jumps to 5 seconds, something is wrong.

Response time trends:
A gradual slowdown often indicates growing database issues, plugin conflicts, or hosting problems.

Time to first byte (TTFB):
This measures server-side performance specifically. A high TTFB points to PHP or database problems, not just large page sizes.

Common Causes of WordPress Slowdowns

  • Plugin conflicts after updates
  • Database tables getting bloated
  • Too many database queries per page load
  • PHP memory limits being hit
  • Hosting server overload
  • Malware running in the background
  • Unoptimized images

When your monitoring shows response times increasing, investigate before it becomes downtime.

WordPress Cron Monitoring

WordPress has its own task scheduler called WP-Cron.

It handles scheduled posts, plugin updates, email queues, backup schedules, and more. If WP-Cron stops working, these tasks silently fail.

Why WP-Cron Breaks

WP-Cron runs when someone visits your site. If your site has low traffic, cron jobs might not run on schedule.

Some hosting providers disable WP-Cron and replace it with server cron. If this isn't set up correctly, nothing runs.

Caching plugins can sometimes interfere with WP-Cron execution.

What to Monitor

WP-Cron accessibility:

https://yoursite.com/wp-cron.php

If this URL returns an error, your scheduled tasks aren't running.

Alternative: Monitor a timestamp file
Some developers set up a simple timestamp check. A cron job updates a file with the current time. Monitoring checks that the timestamp is recent.

If you rely on scheduled tasks for backups, email sending, or inventory updates, monitor your cron health.

What to Look for in a WordPress Monitoring Tool

Not all monitoring tools handle WordPress well.

Here's your checklist for choosing the right one.

Must-Have Features

Cache-bypass URL parameter support:
Can you add ?site_check=1 to your monitored URL? If not, your monitoring will miss cached errors.

Keyword/content monitoring:
Can the tool scan page content for error keywords? This catches database errors, PHP fatal errors, warnings, and notices that return 200 OK.

HTTP status code monitoring:
The tool must alert on non-success status codes above 201. A 500 error with a pretty error page is still a 500 error.

PHP error detection:
Monitor for fatal errors, parse errors, warnings, and notices. These indicate code problems even when pages partially load.

Multiple geographic locations:
Your site should be checked from different regions. Problems can be location-specific.

Fast check intervals:
For business sites, 5-minute checks are the minimum. For e-commerce, 1-minute checks are better.

Multiple alert channels:
Email is easy to miss. You need SMS or phone calls for critical issues.

SSL certificate monitoring:
Automatic alerts before your certificate expires.

Response time tracking:
Historical data showing performance trends over time.

Nice-to-Have Features

Status page:
A public page showing your site status. Great for transparency with clients and customers.

Team collaboration:
Multiple users with different alert preferences.

Maintenance windows:
Suppress alerts during scheduled maintenance.

API access:
Automate monitor creation and management.

Integrations:
Slack, PagerDuty, webhooks for custom workflows.

Features to Avoid

Plugin-based monitoring:
If the monitoring depends on a WordPress plugin, it can't alert you when WordPress itself is broken. External monitoring is always better.

Single location checks:
One monitoring location can give false positives due to network issues.

Email-only alerts:
Email is too easy to miss for critical downtime alerts.

Common WordPress Issues Monitoring Catches

Here are real scenarios where proper monitoring saves the day.

Plugin Update Breaks Site

You update a plugin. It has a bug. Your site shows a white screen.

With monitoring: Alert within minutes. You roll back before most visitors notice.

Without monitoring: Hours of downtime before someone tells you.

Database Connection Lost

Your hosting provider has a database hiccup. WordPress can't connect.

With keyword monitoring: Alert immediately when "Error establishing a database connection" appears.

Without monitoring: Your cache keeps serving pages for a while, then everything breaks.

Memory Limit Exceeded

A plugin starts using too much memory. PHP crashes on certain pages.

With keyword monitoring: Alert when "Allowed memory size exhausted" appears.

Without monitoring: Some pages work, some don't. Customers complain eventually.

SSL Certificate Expires

You forget to renew. Visitors see scary security warnings.

With SSL monitoring: Alerts 30 days before expiration.

Without monitoring: You find out when someone tweets about your "unsafe" site.

Malware Injection

Your site gets hacked. Malware is injected into your pages.

With keyword monitoring: Alert when suspicious keywords appear (pharma spam, redirects, etc.)

Without monitoring: Google blacklists your site before you know there's a problem.

Scheduled Maintenance Mode Stuck

WordPress update gets stuck. Your site shows "Briefly unavailable for scheduled maintenance" forever.

With keyword monitoring: Alert when maintenance message appears.

Without monitoring: Hours of downtime for a 30-second update.

Setting Up WordPress Monitoring: Quick Start

Ready to set up monitoring for your WordPress site? Here's how to start.

Step 1: Configure Cache Bypass

Add this rule to your caching plugin: bypass cache when URL contains site_check=1.

WP Super Cache: Settings → Advanced → Accepted Filenames & Rejected URIs → Add site_check

W3 Total Cache: Page Cache → Never cache pages that contain these query strings → Add site_check

WP Rocket: WP Rocket → Advanced Rules → Never Cache Query Strings → Add site_check

LiteSpeed Cache: Cache → Excludes → Query Strings → Add site_check

Step 2: Set Up Homepage Monitor

Create a monitor for:

https://yoursite.com/?site_check=1

Add keyword monitoring for:

  • "Error establishing a database connection"
  • "Fatal error"
  • "There has been a critical error"

Step 3: Add SSL Monitoring

Enable SSL certificate monitoring with alerts at 30, 14, and 7 days before expiration.

Step 4: Configure Alerts

Set up at least two alert methods:

  • Email for all issues
  • SMS for critical downtime

Step 5: Add Critical Pages

If you run WooCommerce or a membership site, add monitors for:

  • /wp-login.php
  • /checkout/ (WooCommerce)
  • /my-account/ (WooCommerce)
  • Your most important landing pages

Conclusion

WordPress sites need WordPress-specific monitoring.

Generic uptime checks miss cached errors, database problems, and PHP crashes. They report everything is fine while your visitors see error messages.

The key features you need:

  • Cache-bypass monitoring to check the real site, not the cache
  • Keyword monitoring to catch WordPress error messages
  • SSL monitoring to prevent certificate expiration surprises
  • Multiple alert channels like email plus SMS for critical issues
  • Fast check intervals to know about problems in minutes, not hours

Don't wait for customers to tell you your site is broken. Set up proper monitoring and catch issues before they impact your business.

Monitor Your WordPress Site with Monitor.cx

Monitor.cx is built for WordPress site owners who need reliable monitoring.

What we offer:

  • Cache-bypass URL parameter support
  • Keyword monitoring for WordPress errors
  • SSL certificate expiration alerts
  • Multiple global monitoring locations
  • SMS and email alerts
  • Fast check intervals
  • Easy setup in minutes

Stop guessing about your site's health. Start monitoring properly.

Your visitors deserve a working website. Give it to them.