Using WordPress ‘debug_information’ PHP filter

The debug_information WordPress PHP filter allows plugins or themes to add custom debug information to the Tools -> Site Health -> Info screen without creating additional admin pages.

Usage

add_filter( 'debug_information', 'my_custom_debug_info' );

function my_custom_debug_info( $debug_info ) {
    // your custom code here

    return $debug_info;
}

Parameters

$debug_info (array) – The debug information to be added to the core information page.

More information

See WordPress Developer Resources: debug_information

Examples

Add a custom section with basic information

Add a new custom section to Site Health with two fields showing information about the custom theme.

add_filter( 'debug_information', 'my_custom_theme_info' );

function my_custom_theme_info( $debug_info ) {
    $debug_info['my_custom_theme'] = array(
        'label'       => 'My Custom Theme',
        'description' => 'This section shows information about My Custom Theme.',
        'fields'      => array(
            'theme_version' => array(
                'label' => 'Theme Version',
                'value' => '1.0.0',
            ),
            'author' => array(
                'label' => 'Author',
                'value' => 'John Doe',
            ),
        ),
    );

    return $debug_info;
}

Add field to an existing section

Add a new field to the existing WordPress Constants section to display the custom constant value.

add_filter( 'debug_information', 'add_custom_constant' );

function add_custom_constant( $debug_info ) {
    $debug_info['wp-constants']['fields']['my_custom_constant'] = array(
        'label' => 'MY_CUSTOM_CONSTANT',
        'value' => MY_CUSTOM_CONSTANT,
    );

    return $debug_info;
}

Add private information

Add a new custom section with an API key that should not be included in copied data.

add_filter( 'debug_information', 'add_private_api_key_info' );

function add_private_api_key_info( $debug_info ) {
    $debug_info['my_private_api_key'] = array(
        'label'  => 'My Private API Key',
        'fields' => array(
            'api_key' => array(
                'label'   => 'API Key',
                'value'   => '1234567890abcdef',
                'private' => true,
            ),
        ),
    );

    return $debug_info;
}

Display an array of data

Add a new custom section with an array of data displayed as name/value pairs.

add_filter( 'debug_information', 'add_custom_array_data' );

function add_custom_array_data( $debug_info ) {
    $debug_info['my_custom_data'] = array(
        'label'  => 'My Custom Data',
        'fields' => array(
            'data_array' => array(
                'label' => 'Data Array',
                'value' => array(
                    'key1' => 'value1',
                    'key2' => 'value2',
                ),
            ),
        ),
    );

    return $debug_info;
}