Title: WP_Theme_JSON::sanitize_viewport_settings
Published: August 20, 2026

---

# WP_Theme_JSON::sanitize_viewport_settings( mixed $viewport_settings ): array

## In this article

 * [Description](https://developer.wordpress.org/reference/classes/wp_theme_json/sanitize_viewport_settings/?output_format=md#description)
 * [Parameters](https://developer.wordpress.org/reference/classes/wp_theme_json/sanitize_viewport_settings/?output_format=md#parameters)
 * [Return](https://developer.wordpress.org/reference/classes/wp_theme_json/sanitize_viewport_settings/?output_format=md#return)
 * [Source](https://developer.wordpress.org/reference/classes/wp_theme_json/sanitize_viewport_settings/?output_format=md#source)
 * [Changelog](https://developer.wordpress.org/reference/classes/wp_theme_json/sanitize_viewport_settings/?output_format=md#changelog)

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

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

Sanitizes and normalizes viewport breakpoint settings.

## 󠀁[Description](https://developer.wordpress.org/reference/classes/wp_theme_json/sanitize_viewport_settings/?output_format=md#description)󠁿

Keeps only supported breakpoint keys, trims valid CSS lengths, and returns the default
breakpoints when no valid custom breakpoint is provided. When only one breakpoint
is valid, it remains keyed by its configured state and uses a single max-width media
query. When `tablet` is not larger than `mobile`, it is removed.

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

 `$viewport_settings`mixedrequired

Viewport settings from theme.json.

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

 array Sanitized viewport breakpoint settings.

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

    ```php
    private static function sanitize_viewport_settings( $viewport_settings ) {
    	if ( ! is_array( $viewport_settings ) ) {
    		return static::DEFAULT_VIEWPORT_BREAKPOINTS;
    	}

    	$breakpoints = array();
    	foreach ( array_keys( static::DEFAULT_VIEWPORT_BREAKPOINTS ) as $breakpoint ) {
    		$value = $viewport_settings[ $breakpoint ] ?? null;
    		$px    = static::get_viewport_breakpoint_value_in_pixels( $value );
    		if ( null !== $px ) {
    			$breakpoints[ $breakpoint ] = array(
    				'value' => trim( $value ),
    				'px'    => $px,
    			);
    		}
    	}

    	if ( empty( $breakpoints ) ) {
    		return static::DEFAULT_VIEWPORT_BREAKPOINTS;
    	}

    	if ( 1 === count( $breakpoints ) ) {
    		$breakpoint = key( $breakpoints );
    		return array( $breakpoint => $breakpoints[ $breakpoint ]['value'] );
    	}

    	$sanitized = array( 'mobile' => $breakpoints['mobile']['value'] );

    	if ( isset( $breakpoints['tablet'] ) && $breakpoints['mobile']['px'] < $breakpoints['tablet']['px'] ) {
    		$sanitized['tablet'] = $breakpoints['tablet']['value'];
    	}

    	return $sanitized;
    }
    ```

[View all references](https://developer.wordpress.org/reference/files/wp-includes/class-wp-theme-json.php/)
[View on Trac](https://core.trac.wordpress.org/browser/tags/7.1/src/wp-includes/class-wp-theme-json.php#L826)
[View on GitHub](https://github.com/WordPress/wordpress-develop/blob/7.1/src/wp-includes/class-wp-theme-json.php#L826-L859)

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

| Version | Description | 
| [7.1.0](https://developer.wordpress.org/reference/since/7.1.0/) | Introduced. |

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