# Keep Selectors in WP Rocket's "Remove Unused CSS"

> Adds CSS selectors and stylesheet URLs that WP Rocket's Remove Unused CSS must always keep, such as classes added by JavaScript for menus, sliders and pop-ups, so those elements do not lose their styling.

- Type: PHP
- Runs: Run everywhere
- Category: [Plugin Integrations](https://wpide.com/library/category/integrations/)
- Tags: wp-rocket, css, performance
- Author: WPIDE Team
- Installs: 0
- Updated: 2026-10-28
- Page: https://wpide.com/library/rocket-rucss-safelist/

## Code

```php
$wpide_safelist = array( '.menu-open', '.is-active', '.modal-open', '/wp-content/plugins/slider/(.*).css' ); // Selectors or CSS file patterns.

add_filter( 'rocket_rucss_safelist', function ( $safelist ) use ( $wpide_safelist ) {
    return array_values( array_unique( array_merge( (array) $safelist, $wpide_safelist ) ) );
} );
```

## Notes

Use selectors (.menu-open, #popup) or partial stylesheet paths (/plugins/slider/). Clear the Used CSS in WP Rocket afterwards.

## How to use it

Install the free WPIDE plugin (https://wordpress.org/plugins/wpide/), find "Keep Selectors in WP Rocket's "Remove Unused CSS"" in its snippet library and add it in one click; or create a new PHP snippet in WPIDE (or any code snippets plugin) and paste the code above. More snippets: https://wpide.com/library/