WordPress Bootstrap Constants

Last updated: March 4, 2026

Constants defined during WordPress initialization. Many can be overridden in wp-config.php.

Version Constants

Defined in wp-includes/version.php:

Constant	Value	Purpose
`$wp_version`	`'6.9.1'`	WordPress version string
`$wp_db_version`	`60717`	Database schema version
`$tinymce_version`	`'49110-20250317'`	TinyMCE version
`$required_php_version`	`'7.2.24'`	Minimum PHP version
`$required_php_extensions`	`['json', 'hash']`	Required PHP extensions
`$required_mysql_version`	`'5.5.5'`	Minimum MySQL version

Size Constants

Defined in wp_initial_constants():

php

define( 'KB_IN_BYTES', 1024 );
define( 'MB_IN_BYTES', 1024 * KB_IN_BYTES );         // 1,048,576
define( 'GB_IN_BYTES', 1024 * MB_IN_BYTES );         // 1,073,741,824
define( 'TB_IN_BYTES', 1024 * GB_IN_BYTES );         // 1,099,511,627,776
define( 'PB_IN_BYTES', 1024 * TB_IN_BYTES );
define( 'EB_IN_BYTES', 1024 * PB_IN_BYTES );
define( 'ZB_IN_BYTES', 1024 * EB_IN_BYTES );
define( 'YB_IN_BYTES', 1024 * ZB_IN_BYTES );

Since: 4.4.0 (PB through YB added in 6.0.0)

Time Constants

Defined in wp_initial_constants():

php

define( 'MINUTE_IN_SECONDS', 60 );
define( 'HOUR_IN_SECONDS', 60 * MINUTE_IN_SECONDS );     // 3,600
define( 'DAY_IN_SECONDS', 24 * HOUR_IN_SECONDS );        // 86,400
define( 'WEEK_IN_SECONDS', 7 * DAY_IN_SECONDS );         // 604,800
define( 'MONTH_IN_SECONDS', 30 * DAY_IN_SECONDS );       // 2,592,000
define( 'YEAR_IN_SECONDS', 365 * DAY_IN_SECONDS );       // 31,536,000

Note: These are approximations. Use DateTime class for precise calculations.

Since: 3.5.0 (MONTH_IN_SECONDS added in 4.4.0)

Memory Constants

Defined in wp_initial_constants():

Constant	Default	Purpose
`WP_MEMORY_LIMIT`	`'40M'` (single) / `'64M'` (multisite)	Normal memory limit
`WP_MAX_MEMORY_LIMIT`	`'256M'`	Admin memory limit

Override in wp-config.php:

php

define( 'WP_MEMORY_LIMIT', '128M' );
define( 'WP_MAX_MEMORY_LIMIT', '512M' );

Debug Constants

Defined in wp_initial_constants():

Constant	Default	Purpose
`WP_DEBUG`	`false`	Enable debug mode
`WP_DEBUG_DISPLAY`	`true`	Display errors
`WP_DEBUG_LOG`	`false`	Log errors to file

Configuration Examples:

php

// Development setup
define( 'WP_DEBUG', true );
define( 'WP_DEBUG_DISPLAY', true );
define( 'WP_DEBUG_LOG', true );

// Production setup with logging
define( 'WP_DEBUG', true );
define( 'WP_DEBUG_DISPLAY', false );
define( 'WP_DEBUG_LOG', '/path/to/debug.log' );

// Use global display_errors setting
define( 'WP_DEBUG_DISPLAY', null );

Development Constants

Constant	Default	Purpose
`WP_DEVELOPMENT_MODE`	`''`	Development mode (`core`, `plugin`, `theme`, `all`)
`SCRIPT_DEBUG`	`false`	Load unminified scripts/styles

Configuration:

php

define( 'WP_DEVELOPMENT_MODE', 'theme' );
define( 'SCRIPT_DEBUG', true );

Cache Constants

Constant	Default	Purpose
`WP_CACHE`	`false`	Enable advanced-cache.php

Path Constants

Core Paths

Constant	Default	Purpose
`ABSPATH`	WordPress root	Base directory
`WPINC`	`'wp-includes'`	Includes directory name
`WP_CONTENT_DIR`	`ABSPATH . 'wp-content'`	Content directory path
`WP_CONTENT_URL`	`site_url() . '/wp-content'`	Content directory URL

Plugin Paths

Defined in wp_plugin_directory_constants():

Constant	Default	Purpose
`WP_PLUGIN_DIR`	`WP_CONTENT_DIR . '/plugins'`	Plugins directory path
`WP_PLUGIN_URL`	`WP_CONTENT_URL . '/plugins'`	Plugins directory URL
`PLUGINDIR`	`'wp-content/plugins'`	Relative plugins path (deprecated)
`WPMU_PLUGIN_DIR`	`WP_CONTENT_DIR . '/mu-plugins'`	MU-plugins path
`WPMU_PLUGIN_URL`	`WP_CONTENT_URL . '/mu-plugins'`	MU-plugins URL
`MUPLUGINDIR`	`'wp-content/mu-plugins'`	Relative MU-plugins path (deprecated)

Language Paths

Defined in wp_set_lang_dir():

Constant	Default	Purpose
`WP_LANG_DIR`	`WP_CONTENT_DIR . '/languages'`	Language files path
`LANGDIR`	`'wp-content/languages'`	Relative language path (deprecated)

Template Paths

Defined in wp_templating_constants():

Constant	Purpose	Deprecated
`TEMPLATEPATH`	Current template directory	6.4.0
`STYLESHEETPATH`	Current stylesheet directory	6.4.0

Use instead: get_template_directory() and get_stylesheet_directory()

Defined in wp_cookie_constants():

Constant	Default	Purpose
`COOKIEHASH`	`md5(siteurl)`	Unique hash for cookies
`USER_COOKIE`	`'wordpressuser_' . COOKIEHASH`	User cookie name
`PASS_COOKIE`	`'wordpresspass_' . COOKIEHASH`	Password cookie name
`AUTH_COOKIE`	`'wordpress_' . COOKIEHASH`	Auth cookie name
`SECURE_AUTH_COOKIE`	`'wordpress_sec_' . COOKIEHASH`	Secure auth cookie
`LOGGED_IN_COOKIE`	`'wordpress_logged_in_' . COOKIEHASH`	Logged-in cookie
`TEST_COOKIE`	`'wordpress_test_cookie'`	Test cookie name
`COOKIEPATH`	`'/'` (home path)	Cookie path
`SITECOOKIEPATH`	Site path	Site cookie path
`ADMIN_COOKIE_PATH`	`SITECOOKIEPATH . 'wp-admin'`	Admin cookie path
`PLUGINS_COOKIE_PATH`	Plugins URL path	Plugins cookie path
`COOKIE_DOMAIN`	`''`	Cookie domain
`RECOVERY_MODE_COOKIE`	`'wordpress_rec_' . COOKIEHASH`	Recovery mode cookie

SSL Constants

Defined in wp_ssl_constants():

Constant	Default	Purpose
`FORCE_SSL_ADMIN`	`true` if site uses HTTPS	Force SSL for admin
`FORCE_SSL_LOGIN`	N/A	Deprecated in 4.0.0

Functionality Constants

Defined in wp_functionality_constants():

Constant	Default	Purpose
`AUTOSAVE_INTERVAL`	`60` (1 minute)	Autosave interval in seconds
`EMPTY_TRASH_DAYS`	`30`	Days before trash auto-empties
`WP_POST_REVISIONS`	`true`	Enable post revisions
`WP_CRON_LOCK_TIMEOUT`	`60`	Cron lock timeout in seconds

Disable revisions:

php

define( 'WP_POST_REVISIONS', false );

Limit revisions:

php

define( 'WP_POST_REVISIONS', 5 );

Theme Constants

Defined in wp_templating_constants():

Constant	Default	Purpose
`WP_DEFAULT_THEME`	`'twentytwentyfive'`	Fallback theme

Media Constants

Constant	Default	Purpose
`MEDIA_TRASH`	`false`	Enable media trash

Environment Constants

Constant	Default	Purpose
`WP_ENVIRONMENT_TYPE`	`'production'`	Environment type

Values: 'local', 'development', 'staging', 'production'

Request Type Constants

Set during request processing:

Constant	Purpose
`WP_ADMIN`	Admin request
`WP_BLOG_ADMIN`	Site admin request
`WP_NETWORK_ADMIN`	Network admin request
`WP_USER_ADMIN`	User admin request
`DOING_AJAX`	AJAX request
`DOING_CRON`	Cron request
`REST_REQUEST`	REST API request
`XMLRPC_REQUEST`	XML-RPC request
`WP_INSTALLING`	Installation in progress

Special Load Constants

Constant	Purpose
`SHORTINIT`	Minimal bootstrap (skip plugins, themes)
`WP_USE_THEMES`	Load themes (default `true`)
`WP_SANDBOX_SCRAPING`	Error scraping mode
`IFRAME_REQUEST`	Request in iframe

Security Constants

Constant	Default	Purpose
`DISALLOW_FILE_MODS`	`false`	Disable plugin/theme editor
`DISALLOW_FILE_EDIT`	`false`	Disable file editor only
`DISALLOW_UNFILTERED_HTML`	`false`	Disable unfiltered HTML
`ALLOW_UNFILTERED_UPLOADS`	`false`	Allow unfiltered file uploads
`AUTOMATIC_UPDATER_DISABLED`	`false`	Disable auto-updates

Multisite Constants

Constant	Purpose
`MULTISITE`	Multisite enabled
`SUBDOMAIN_INSTALL`	Subdomain multisite
`DOMAIN_CURRENT_SITE`	Main site domain
`PATH_CURRENT_SITE`	Main site path
`SITE_ID_CURRENT_SITE`	Main network ID
`BLOG_ID_CURRENT_SITE`	Main site ID
`SUNRISE`	Load sunrise.php

Feature Constants

Constant	Purpose
`WP_FEATURE_BETTER_PASSWORDS`	Better password handling available

Timestamp Constants

Constant	Purpose
`WP_START_TIMESTAMP`	Request start time (microtime)

Defining Constants

Constants should be defined in wp-config.php before require_once ABSPATH . 'wp-settings.php':

php

// Example wp-config.php

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

// Memory limits
define( 'WP_MEMORY_LIMIT', '256M' );
define( 'WP_MAX_MEMORY_LIMIT', '512M' );

// Custom content directory
define( 'WP_CONTENT_DIR', '/var/www/content' );
define( 'WP_CONTENT_URL', 'https://example.com/content' );

// Custom plugin directory
define( 'WP_PLUGIN_DIR', '/var/www/content/plugins' );
define( 'WP_PLUGIN_URL', 'https://example.com/content/plugins' );

// Revisions
define( 'WP_POST_REVISIONS', 10 );
define( 'AUTOSAVE_INTERVAL', 120 );

// Security
define( 'DISALLOW_FILE_EDIT', true );
define( 'FORCE_SSL_ADMIN', true );

// Cron
define( 'DISABLE_WP_CRON', true );  // If using system cron
define( 'ALTERNATE_WP_CRON', true ); // Alternative cron method

// Must be last
require_once ABSPATH . 'wp-settings.php';

Checking Constants

php

// Check if defined
if ( defined( 'WP_DEBUG' ) && WP_DEBUG ) {
    // Debug mode is on
}

// Check specific value
if ( defined( 'WP_ENVIRONMENT_TYPE' ) ) {
    $env = WP_ENVIRONMENT_TYPE;
} else {
    $env = 'production';
}

// Use helper functions when available
if ( function_exists( 'wp_get_environment_type' ) ) {
    $env = wp_get_environment_type();
}

View on GitHub

WordPress Bootstrap Constants

Version Constants

Size Constants

Time Constants

Memory Constants

Debug Constants

Development Constants

Cache Constants

Path Constants

Core Paths

Plugin Paths

Language Paths

Template Paths

Cookie Constants

SSL Constants

Functionality Constants

Theme Constants

Media Constants

Environment Constants

Request Type Constants

Special Load Constants

Security Constants

Multisite Constants

Feature Constants

Timestamp Constants

Defining Constants

Checking Constants

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