KeenWP

Curated resource guide

WordPress Debugging and Profiling Resources

Move from guesswork to evidence when diagnosing WordPress failures and slowdowns. This collection covers logs, Query Monitor, Xdebug, browser tools, database analysis, API and cron debugging, PHP profiling, APM, intermittent faults, and production-safe techniques for finding the real source of a problem.

Scope

What this guide covers

  • WP_DEBUG and related constants
  • debug.log
  • PHP error logging
  • Query Monitor
  • Debug Bar
  • Xdebug
  • stack traces
  • breakpoints
  • database query analysis
  • HTTP API debugging
  • REST API debugging
  • AJAX
  • cron
  • email
  • hooks
  • object cache
  • transients
  • rewrite rules
  • permissions
  • fatal-error recovery
  • browser DevTools
  • JavaScript errors
  • network waterfalls
  • PHP profiling
  • slow query logs
  • APM tools
  • production-safe debugging
  • memory leaks
  • race conditions
  • intermittent issues
  • and reproducible troubleshooting workflows

Selected references

Curated resources

Links open the original publisher so you can use the complete, current material in context.

  1. 01
    5
    Recommended starting point

    Debugging in WordPress

    Official guidance for debug constants, logs, script diagnostics, and safe investigation during local development.

    developer.wordpress.org
  2. 02
    5

    Query Monitor

    See query timing, PHP errors, HTTP requests, hooks, scripts, and request context while diagnosing WordPress.

    wordpress.org
  3. 03
    5

    Xdebug Step Debugging

    Configure breakpoints and request triggers to inspect WordPress execution instead of adding temporary output.

    xdebug.org
  4. 04
    5

    Xdebug Profiler

    Collect call-level timing and memory profiles for evidence-based backend performance work.

    xdebug.org
  5. 05
    5

    PHP Error Reporting

    Use the PHP runtime reference when selecting diagnostic levels across development and production.

    php.net
  6. 06
    5

    Chrome DevTools Performance

    Record browser work, network activity, layout, scripting, and rendering while debugging frontend behavior.

    developer.chrome.com
  7. 07
    4

    Debug Bar

    Add a lightweight WordPress admin debug panel that other diagnostic extensions can integrate with.

    wordpress.org