Title: block_parser_class
Published: December 6, 2018
Last modified: February 24, 2026

---

# apply_filters( ‘block_parser_class’, string $parser_class )

## In this article

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

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

Filter to allow plugins to replace the server-side block parser.

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

 `$parser_class`string

Name of block parser class.

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

    ```php
    $parser_class = apply_filters( 'block_parser_class', 'WP_Block_Parser' );
    ```

[View all references](https://developer.wordpress.org/reference/files/wp-includes/blocks.php/)
[View on Trac](https://core.trac.wordpress.org/browser/tags/6.9.4/src/wp-includes/blocks.php#L2427)
[View on GitHub](https://github.com/WordPress/wordpress-develop/blob/6.9.4/src/wp-includes/blocks.php#L2427-L2427)

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

| Used by | Description | 
| [parse_blocks()](https://developer.wordpress.org/reference/functions/parse_blocks/)`wp-includes/blocks.php` |

Parses blocks out of a content string.

  |

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

| Version | Description | 
| [5.0.0](https://developer.wordpress.org/reference/since/5.0.0/) | Introduced. |

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