You installed Query Monitor to debug your site. Now you see red error numbers everywhere. But your site works fine. Visitors see no problems. That is frustrating because you do not know which errors matter.
A common issue is that Query Monitor shows warnings and notices that WordPress suppresses by default. These are not fatal errors. Your site works because WordPress recovers automatically. The plugin is not broken. It shows you everything, including harmless issues.
Why Query Monitor Shows Errors That Do Not Break Your Site
WordPress has error levels: fatal errors, warnings, notices, and deprecations. Fatal errors break sites. Warnings and notices are logged but do not stop execution. Query Monitor shows all levels. Your site works because warnings are not fatal.
This is not Query Monitor being bad. It shows complete picture. Most issues are harmless.
Which Errors You Can Safely Ignore
- “Undefined index” notices (PHP trying to access missing array key)
- “Undefined variable” warnings (variable used before set)
- Deprecation notices (code will break in future PHP version)
- Duplicate queries (performance issue but not breaking)
- Slow queries (performance issue but site works)
These need fixing but do not require immediate panic.
Which Errors Require Immediate Action
Fatal errors (white screen). Database connection errors. Memory exhausted errors (site may break on next page load). “Allowed memory size exhausted” (may break random pages). Syntax errors in active plugins or themes.
Fix these immediately. Your site may break for users.
How to Use Query Monitor Like a Pro
- Ignore notices and warnings first time
- Look for “PHP Errors” section (red badge)
- Check “Duplicate Queries” for performance
- Check “Slow Queries” (over 0.05 seconds)
- Check “HTTP API Calls” for external requests
- Fix most important issues first
Not all red numbers are equal. Prioritize fatal errors and performance issues.
People Also Ask About Query Monitor Errors
Why does Query Monitor show errors when my site works fine?
Because warnings and notices do not break sites. WordPress handles them.
Should I ignore all Query Monitor errors?
No. Check for fatal errors and memory issues. Fix those. Warnings can wait.
Is Query Monitor worse than Debug Bar for error detection?
Debug Bar shows similar information. Query Monitor is better but both show non-fatal issues.
How to Hide Certain Errors in Query Monitor
Add to wp-config.php: define('WP_DEBUG_DISPLAY', false); This hides errors from display but Query Monitor still shows them. Or ignore specific error types in Query Monitor settings.
Hiding is not fixing. Fix issues eventually.
Related Debugging Plugins With Different Approaches
If Query Monitor shows too much noise, try Debug This or Log Deprecated Notices. Some site owners prefer WP Server Stats for focused monitoring.
Query Monitor is powerful but overwhelming. Learn to filter.
Final Thoughts
If Query Monitor shows errors but site works, do not panic. Check if errors are warnings/notices (harmless) or fatal (serious). Fix fatal errors first. Fix warnings when time allows. Ignore nothing forever but prioritize wisely.
Query Monitor shows truth. Truth includes harmless issues. Learn to distinguish.