WP_MEMORY_LIMIT and PHP memory_limit look similar but operate at different layers. This guide explains how they interact, what WP_MAX_MEMORY_LIMIT does for admin requests, how memory_get_peak_usage() reveals the truth, and the four situations where WordPress silently ignores your settings entirely.
A complete categorized reference to every important wp-config.php constant: debug, memory, performance, security, paths, cron, multisite, and more. With real code examples for development, staging, and production environments.
The WordPress White Screen of Death (WSOD) shows a blank page with no error message. This step-by-step guide covers enabling WP_DEBUG, fixing memory limits, isolating plugin and theme conflicts, using WordPress Recovery Mode, and preventing WSOD from happening again.
Learn how to debug WordPress AJAX requests step by step. Covers the admin-ajax.php flow, wp_ajax_* hooks, nonce failures, Network tab inspection, wp_send_json_success usage, DOING_AJAX constant, and a complete troubleshooting workflow with PHP and JavaScript code examples.
WP-Cron stops running silently and the cause is almost always a stuck lock, a blocked loopback request, or DISABLE_WP_CRON set without a server cron replacement. This guide covers the full diagnostic flow with WP-CLI, _get_cron_array(), WP_CRON_LOCK_TIMEOUT, object cache conflicts, and real cron setup.
WordPress error logs stop being intimidating once you understand their structure. This guide decodes every PHP error severity level (Fatal, Warning, Notice, Deprecated, Parse), shows how to read stack traces, documents the most common WordPress-specific errors with root causes and fixes, explains error_reporting levels, and covers log security and rotation.
Query Monitor is not just a queries plugin – it is a complete execution inspector for every WordPress request. This tutorial explains every panel: Queries (duplicates, slow queries, component filter), Hooks, HTTP API, PHP Errors, Scripts and Styles, Languages, Conditionals, Environment, Capabilities, Blocks, Caches, and REST API. Real debugging workflows with each panel.
Most developers set WP_DEBUG and stop there. This guide documents every WordPress debug constant in wp-config.php: WP_DEBUG, WP_DEBUG_LOG, WP_DEBUG_DISPLAY, SCRIPT_DEBUG, SAVEQUERIES, WP_CACHE, CONCATENATE_SCRIPTS, and more. Includes correct configurations for local development, staging, and production, plus how to use ini_set for custom error log paths.
