Title: WP_Customize_Manager::wp_die
Published: April 25, 2014
Last modified: May 20, 2026

---

# WP_Customize_Manager::wp_die( string|WP_Error $ajax_message, string $message = null )

## In this article

 * [Parameters](https://developer.wordpress.org/reference/classes/wp_customize_manager/wp_die/?output_format=md#parameters)
 * [Source](https://developer.wordpress.org/reference/classes/wp_customize_manager/wp_die/?output_format=md#source)
 * [Related](https://developer.wordpress.org/reference/classes/wp_customize_manager/wp_die/?output_format=md#related)
 * [Changelog](https://developer.wordpress.org/reference/classes/wp_customize_manager/wp_die/?output_format=md#changelog)

[ Back to top](https://developer.wordpress.org/reference/classes/wp_customize_manager/wp_die/?output_format=md#wp--skip-link--target)

Custom wp_die wrapper. Returns either the standard message for UI or the Ajax message.

## 󠀁[Parameters](https://developer.wordpress.org/reference/classes/wp_customize_manager/wp_die/?output_format=md#parameters)󠁿

 `$ajax_message`string|[WP_Error](https://developer.wordpress.org/reference/classes/wp_error/)
required

Ajax return.

`$message`stringoptional

UI message.

Default:`null`

## 󠀁[Source](https://developer.wordpress.org/reference/classes/wp_customize_manager/wp_die/?output_format=md#source)󠁿

    ```php
    protected function wp_die( $ajax_message, $message = null ) {
    	if ( $this->doing_ajax() ) {
    		wp_die( $ajax_message );
    	}

    	if ( ! $message ) {
    		$message = __( 'An error occurred while customizing. Please refresh the page and try again.' );
    	}

    	if ( $this->messenger_channel ) {
    		ob_start();
    		wp_enqueue_scripts();
    		wp_print_scripts( array( 'customize-base' ) );

    		$settings = array(
    			'messengerArgs' => array(
    				'channel' => $this->messenger_channel,
    				'url'     => wp_customize_url(),
    			),
    			'error'         => $ajax_message,
    		);
    		$message .= ob_get_clean();
    		ob_start();
    		?>
    		<script>
    		( function( api, settings ) {
    			var preview = new api.Messenger( settings.messengerArgs );
    			preview.send( 'iframe-loading-error', settings.error );
    		} )( wp.customize, <?php echo wp_json_encode( $settings, JSON_HEX_TAG | JSON_UNESCAPED_SLASHES ); ?> );
    		</script>
    		<?php
    		$message .= wp_get_inline_script_tag( wp_remove_surrounding_empty_script_tags( ob_get_clean() ) . "\n//# sourceURL=" . rawurlencode( __METHOD__ ) );
    	}

    	wp_die( $message );
    }
    ```

[View all references](https://developer.wordpress.org/reference/files/wp-includes/class-wp-customize-manager.php/)
[View on Trac](https://core.trac.wordpress.org/browser/tags/7.0/src/wp-includes/class-wp-customize-manager.php#L451)
[View on GitHub](https://github.com/WordPress/wordpress-develop/blob/7.0/src/wp-includes/class-wp-customize-manager.php#L451-L486)

## 󠀁[Related](https://developer.wordpress.org/reference/classes/wp_customize_manager/wp_die/?output_format=md#related)󠁿

| Uses | Description | 
| [wp_remove_surrounding_empty_script_tags()](https://developer.wordpress.org/reference/functions/wp_remove_surrounding_empty_script_tags/)`wp-includes/script-loader.php` |

Removes leading and trailing _empty_ script tags.

  | 
| [wp_get_inline_script_tag()](https://developer.wordpress.org/reference/functions/wp_get_inline_script_tag/)`wp-includes/script-loader.php` |

Constructs an inline script tag.

  | 
| [WP_Customize_Manager::doing_ajax()](https://developer.wordpress.org/reference/classes/wp_customize_manager/doing_ajax/)`wp-includes/class-wp-customize-manager.php` |

Returns true if it’s an Ajax request.

  | 
| [wp_customize_url()](https://developer.wordpress.org/reference/functions/wp_customize_url/)`wp-includes/theme.php` |

Returns a URL to load the Customizer.

  | 
| [wp_print_scripts()](https://developer.wordpress.org/reference/functions/wp_print_scripts/)`wp-includes/functions.wp-scripts.php` |

Prints scripts in document head that are in the $handles queue.

  | 
| [wp_enqueue_scripts()](https://developer.wordpress.org/reference/functions/wp_enqueue_scripts/)`wp-includes/script-loader.php` |

Wrapper for do_action( ‘wp_enqueue_scripts’ ).

  | 
| [wp_json_encode()](https://developer.wordpress.org/reference/functions/wp_json_encode/)`wp-includes/functions.php` |

Encodes a variable into JSON, with some confidence checks.

  | 
| [__()](https://developer.wordpress.org/reference/functions/__/)`wp-includes/l10n.php` |

Retrieves the translation of $text.

  | 
| [wp_die()](https://developer.wordpress.org/reference/functions/wp_die/)`wp-includes/functions.php` |

Kills WordPress execution and displays HTML page with an error message.

  |

[Show 4 more](https://developer.wordpress.org/reference/classes/wp_customize_manager/wp_die/?output_format=md#)
[Show less](https://developer.wordpress.org/reference/classes/wp_customize_manager/wp_die/?output_format=md#)

| Used by | Description | 
| [WP_Customize_Manager::customize_preview_init()](https://developer.wordpress.org/reference/classes/wp_customize_manager/customize_preview_init/)`wp-includes/class-wp-customize-manager.php` |

Prints JavaScript settings.

  | 
| [WP_Customize_Manager::setup_theme()](https://developer.wordpress.org/reference/classes/wp_customize_manager/setup_theme/)`wp-includes/class-wp-customize-manager.php` |

Starts preview and customize theme.

  |

## 󠀁[Changelog](https://developer.wordpress.org/reference/classes/wp_customize_manager/wp_die/?output_format=md#changelog)󠁿

| Version | Description | 
| [3.4.0](https://developer.wordpress.org/reference/since/3.4.0/) | Introduced. |

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