Allows blocks to be hidden on the front-end by returning empty content when visibility is set to false.

Source: wp-includes/block-supports/block-visibility.php
Since: 6.9.0

Support Key

supports.visibility — defaults to true when checking support.

The visibility value is stored in block metadata: $block['attrs']['metadata']['blockVisibility'].

Functions

wp_render_block_visibility_support()

function wp_render_block_visibility_support( string $block_content, array $block ): string

Since: 6.9.0
Access: private

Logic:

1. Gets the registered block type
2. Checks block_has_support( $block_type, 'visibility', true ) — note the true default
3. If $block['attrs']['metadata']['blockVisibility'] is exactly false, returns '' (empty string)
4. Otherwise returns the block content unchanged

Hooks

Notes

• No WP_Block_Supports::register() call — this support is entirely filter-based.
• The default support value is true, meaning blocks support visibility unless they explicitly opt out.
• Only false (boolean) triggers hiding; any other value or absence of the attribute renders normally.