WP_DEVELOPMENT_MODE: All 5 values with full wp-config.php examples (vapvarun.com)

01-core-mode.php

<?php
// wp-config.php — Core development mode
// Use this when you are working on WordPress core patches,
// testing core REST API changes, or running Gutenberg block-editor experiments.

define( 'WP_DEVELOPMENT_MODE', 'core' );

// Pair it with the full debug stack so you catch every notice
define( 'WP_DEBUG',         true );
define( 'WP_DEBUG_LOG',     true );  // writes to wp-content/debug.log
define( 'WP_DEBUG_DISPLAY', false ); // keep screen clean in local browser
define( 'SCRIPT_DEBUG',     true );  // load .dev.js / .dev.css source files

02-plugin-mode.php

<?php
// wp-config.php — Plugin development mode
// Use this when building or debugging a plugin.
// WordPress skips object-cache for plugin assets and avoids
// certain auto-minification behaviors that mask JS errors.

define( 'WP_DEVELOPMENT_MODE', 'plugin' );

define( 'WP_DEBUG',         true );
define( 'WP_DEBUG_LOG',     true );
define( 'WP_DEBUG_DISPLAY', false );
define( 'SCRIPT_DEBUG',     true );

// Useful companion constant: disables concatenation of admin scripts
// so browser DevTools shows real file names, not a merged blob
define( 'CONCATENATE_SCRIPTS', false );

03-theme-mode.php

<?php
// wp-config.php — Theme development mode
// Use this when building custom themes or FSE block themes.
// WordPress bypasses theme stylesheet caching so changes
// appear without a hard refresh or cache-bust query string.

define( 'WP_DEVELOPMENT_MODE', 'theme' );

define( 'WP_DEBUG',         true );
define( 'WP_DEBUG_LOG',     true );
define( 'WP_DEBUG_DISPLAY', false );
define( 'SCRIPT_DEBUG',     true );

// Optional: disable the theme cache when using the WP REST API
// so theme.json changes render immediately in the block editor
define( 'WP_ENVIRONMENT_TYPE', 'development' );

04-all-mode.php

<?php
// wp-config.php — 'all' mode (core + plugin + theme combined)
// Use when you are touching multiple layers at once — for example,
// building a plugin that registers a block that ships with a child theme.
// WordPress 6.4+ recognises 'all' as the catch-all development value.

define( 'WP_DEVELOPMENT_MODE', 'all' );

define( 'WP_DEBUG',         true );
define( 'WP_DEBUG_LOG',     true );
define( 'WP_DEBUG_DISPLAY', false );
define( 'SCRIPT_DEBUG',     true );

05-empty-string-mode.php

<?php
// wp-config.php — empty string '' (development mode OFF)
// Setting WP_DEVELOPMENT_MODE to an empty string is the CORRECT way
// to explicitly disable development mode on staging or production.
// Do NOT simply omit the constant — third-party code may define it.
// An explicit empty string guarantees it is off.

define( 'WP_DEVELOPMENT_MODE', '' );

// On production, also ensure debug is off:
define( 'WP_DEBUG',         false );
define( 'WP_DEBUG_LOG',     false );
define( 'WP_DEBUG_DISPLAY', false );

06-env-aware-config.php

<?php
// wp-config.php — Environment-aware WP_DEVELOPMENT_MODE
// Reads from a .env file or server environment variable.
// Keeps wp-config.php identical across dev / staging / production.
// Works well with Local by Flywheel, Kinsta, or WP Playground.

$env = getenv( 'WP_ENV' ) ?: 'production';

switch ( $env ) {
    case 'development':
        define( 'WP_DEVELOPMENT_MODE', 'all' );
        define( 'WP_DEBUG',            true );
        define( 'WP_DEBUG_LOG',        true );
        define( 'WP_DEBUG_DISPLAY',    false );
        define( 'SCRIPT_DEBUG',        true );
        break;

    case 'staging':
        // Staging mirrors production but keeps debug.log for QA review
        define( 'WP_DEVELOPMENT_MODE', '' );
        define( 'WP_DEBUG',            true );
        define( 'WP_DEBUG_LOG',        true );
        define( 'WP_DEBUG_DISPLAY',    false );
        break;

    default: // production
        define( 'WP_DEVELOPMENT_MODE', '' );
        define( 'WP_DEBUG',            false );
        define( 'WP_DEBUG_LOG',        false );
        define( 'WP_DEBUG_DISPLAY',    false );
        break;
}

07-check-mode-in-code.php

<?php
// How to READ WP_DEVELOPMENT_MODE inside your plugin or theme
// Use wp_get_development_mode() — introduced in WordPress 6.3.
// Returns the current mode string: 'core', 'plugin', 'theme', 'all', or ''.

function myplugin_register_dev_tools(): void {
    // Only load dev tools when in plugin development mode
    if ( 'plugin' === wp_get_development_mode() || 'all' === wp_get_development_mode() ) {
        require_once plugin_dir_path( __FILE__ ) . 'dev/debug-panel.php';
    }
}
add_action( 'plugins_loaded', 'myplugin_register_dev_tools' );


// wp_is_development_mode( $mode ) checks a specific mode
// Returns true when WP_DEVELOPMENT_MODE matches $mode OR equals 'all'
function myplugin_enqueue_debug_assets(): void {
    if ( wp_is_development_mode( 'plugin' ) ) {
        wp_enqueue_style(
            'myplugin-debug',
            plugin_dir_url( __FILE__ ) . 'assets/debug.css',
            [],
            filemtime( plugin_dir_path( __FILE__ ) . 'assets/debug.css' )
        );
    }
}
add_action( 'wp_enqueue_scripts', 'myplugin_enqueue_debug_assets' );

08-multisite-config.php

<?php
// Multisite — per-network WP_DEVELOPMENT_MODE via sunrise.php
// wp-config.php on a multisite network sets WP_DEVELOPMENT_MODE globally.
// To override per-subsite, use a sunrise.php mu-plugin.

// In wp-config.php (before /* That's all... */):
define( 'SUNRISE',              true );  // enable sunrise.php
define( 'WP_DEVELOPMENT_MODE', 'all' ); // default for all subsites

// In wp-content/sunrise.php:
// Override for a specific subsite by blog_id
if ( isset( $current_blog ) && 5 === (int) $current_blog->blog_id ) {
    // Subsite 5 is the staging preview — keep dev mode off there
    if ( ! defined( 'WP_DEVELOPMENT_MODE' ) ) {
        define( 'WP_DEVELOPMENT_MODE', '' );
    }
}

09-playground-blueprint.json

{
  "$schema": "https://playground.wordpress.net/blueprint-schema.json",
  "phpVersion": "8.2",
  "wordPressVersion": "latest",
  "steps": [
    {
      "step": "defineWpConfigConsts",
      "consts": {
        "WP_DEVELOPMENT_MODE": "plugin",
        "WP_DEBUG": true,
        "WP_DEBUG_LOG": true,
        "WP_DEBUG_DISPLAY": false,
        "SCRIPT_DEBUG": true
      }
    },
    {
      "step": "installPlugin",
      "pluginZipFile": {
        "resource": "url",
        "url": "https://github.com/vapvarun/my-plugin/archive/refs/heads/main.zip"
      },
      "options": { "activate": true }
    }
  ]
}