Private AccessPrivate Access

This function’s access is marked private. This means it is not intended for use by plugin or theme developers, only in other core functions. It is listed here for completeness.


Set PHP error reporting based on WordPress debug settings.




Uses three constants: WP_DEBUG, WP_DEBUG_DISPLAY, and WP_DEBUG_LOG. All three can be defined in wp-config.php. By default, WP_DEBUG and WP_DEBUG_LOG are set to false, and WP_DEBUG_DISPLAY is set to true.

When WP_DEBUG is true, all PHP notices are reported. WordPress will also display internal notices: when a deprecated WordPress function, function argument, or file is used. Deprecated code may be removed from a later version.

It is strongly recommended that plugin and theme developers use WP_DEBUG in their development environments.

WP_DEBUG_DISPLAY and WP_DEBUG_LOG perform no function unless WP_DEBUG is true.

When WP_DEBUG_DISPLAY is true, WordPress will force errors to be displayed. WP_DEBUG_DISPLAY defaults to true. Defining it as null prevents WordPress from changing the global configuration setting. Defining WP_DEBUG_DISPLAY as false will force errors to be hidden.

When WP_DEBUG_LOG is true, errors will be logged to wp-content/debug.log. When WP_DEBUG_LOG is a valid path, errors will be logged to the specified file.

Errors are never displayed for XML-RPC, REST, and Ajax requests.


File: wp-includes/load.php



Version Description
5.1.0 WP_DEBUG_LOG can be a file path.
3.0.0 Introduced.
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