Title: maybe_serialize
Published: April 25, 2014
Last modified: February 24, 2026

---

# maybe_serialize( string|array|object $data ): mixed

## In this article

 * [Parameters](https://developer.wordpress.org/reference/functions/maybe_serialize/?output_format=md#parameters)
 * [Return](https://developer.wordpress.org/reference/functions/maybe_serialize/?output_format=md#return)
 * [More Information](https://developer.wordpress.org/reference/functions/maybe_serialize/?output_format=md#more-information)
 * [Source](https://developer.wordpress.org/reference/functions/maybe_serialize/?output_format=md#source)
 * [Related](https://developer.wordpress.org/reference/functions/maybe_serialize/?output_format=md#related)
 * [Changelog](https://developer.wordpress.org/reference/functions/maybe_serialize/?output_format=md#changelog)
 * [User Contributed Notes](https://developer.wordpress.org/reference/functions/maybe_serialize/?output_format=md#user-contributed-notes)

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

Serializes data, if needed.

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

 `$data`string|array|objectrequired

Data that might be serialized.

## 󠀁[Return](https://developer.wordpress.org/reference/functions/maybe_serialize/?output_format=md#return)󠁿

 mixed A scalar data.

## 󠀁[More Information](https://developer.wordpress.org/reference/functions/maybe_serialize/?output_format=md#more-information)󠁿

 * Data might need to be serialized to allow it to be successfully stored and retrieved
   from a database in a form that PHP can understand.
 * Confusingly, strings that contain already serialized values are serialized again,
   resulting in a nested serialization. Other strings are unmodified.
 * A possible solution to prevent nested serialization is to check if a variable
   is serialized using [is_serialized()](https://developer.wordpress.org/reference/functions/is_serialized/)

    ```php
    if( !is_serialized( $data ) ) {
    $data = maybe_serialize($data);
    }
    ```

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

    ```php
    function maybe_serialize( $data ) {
    	if ( is_array( $data ) || is_object( $data ) ) {
    		return serialize( $data );
    	}

    	/*
    	 * Double serialization is required for backward compatibility.
    	 * See https://core.trac.wordpress.org/ticket/12930
    	 * Also the world will end. See WP 3.6.1.
    	 */
    	if ( is_serialized( $data, false ) ) {
    		return serialize( $data );
    	}

    	return $data;
    }
    ```

[View all references](https://developer.wordpress.org/reference/files/wp-includes/functions.php/)
[View on Trac](https://core.trac.wordpress.org/browser/tags/6.9.4/src/wp-includes/functions.php#L628)
[View on GitHub](https://github.com/WordPress/wordpress-develop/blob/6.9.4/src/wp-includes/functions.php#L628-L643)

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

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

Checks value to find if it was serialized.

  |

| Used by | Description | 
| [WP_Site_Health::get_autoloaded_options_size()](https://developer.wordpress.org/reference/classes/wp_site_health/get_autoloaded_options_size/)`wp-admin/includes/class-wp-site-health.php` |

Calculates total amount of autoloaded data.

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

Imports theme starter content into the customized state.

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

Updates the value of a network option that was already added.

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

Adds a new network option.

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

Create WordPress options and set the default values.

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

Update metadata of user.

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

Updates the value of an option that was already added.

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

Adds a new option.

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

Deletes metadata for the specified object.

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

Updates metadata by meta ID.

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

Adds metadata for the specified object.

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

Updates metadata for the specified object. If no value already exists for the specified object ID and metadata key, the metadata will be added.

  |

[Show 7 more](https://developer.wordpress.org/reference/functions/maybe_serialize/?output_format=md#)
[Show less](https://developer.wordpress.org/reference/functions/maybe_serialize/?output_format=md#)

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

| Version | Description | 
| [2.0.5](https://developer.wordpress.org/reference/since/2.0.5/) | Introduced. |

## 󠀁[User Contributed Notes](https://developer.wordpress.org/reference/functions/maybe_serialize/?output_format=md#user-contributed-notes)󠁿

 1.  [Skip to note 2 content](https://developer.wordpress.org/reference/functions/maybe_serialize/?output_format=md#comment-content-1131)
 2.   [Codex](https://profiles.wordpress.org/codex/)  [  10 years ago  ](https://developer.wordpress.org/reference/functions/maybe_serialize/#comment-1131)
 3. [You must log in to vote on the helpfulness of this note](https://login.wordpress.org?redirect_to=https%3A%2F%2Fdeveloper.wordpress.org%2Freference%2Ffunctions%2Fmaybe_serialize%2F%23comment-1131)
    Vote results for this note: 2[You must log in to vote on the helpfulness of this note](https://login.wordpress.org?redirect_to=https%3A%2F%2Fdeveloper.wordpress.org%2Freference%2Ffunctions%2Fmaybe_serialize%2F%23comment-1131)
 4. **Basic Examples**
 5.     ```php
        <?php
    
        // Strings are returned untouched.
        $data = 'Hello World!';
        echo maybe_serialize( $data );
        // Hello World!
    
        // Integers, floats and boolean values are also returned untouched.
        $data = 55;
        echo maybe_serialize( $data );
        // 55
    
        $data = 4.560
        echo maybe_serialize( $data );
        // 4.560
    
        $data = true;
        $data = maybe_serialize( $data );
        // $data = true;
    
        $data = null;
        $data = maybe_serialize( $data );
        // $data = null
    
        // An array or object will be returned as a serialized string.
        $data = array( 1 => 'Hello World!', 'foo' => 'bar' );
        echo maybe_serialize( $data );
        // a:2:{i:1;s:12:"Hello World!";s:3:"foo";s:3:"bar";}
    
        // A serialized string will be serialized again.
        $data = 'a:2:{i:1;s:12:"Hello World!";s:3:"foo";s:3:"bar";}';
        echo maybe_serialize( $data );
        // s:50:"a:2:{i:1;s:12:"Hello World!";s:3:"foo";s:3:"bar";}";
    
        ?>
        ```
    
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