How to exclude specific categories from your blog homepage

Copy the snippet below in your functions.php file. Replace the category IDs on line 3 with the ones you want to exclude. Then save the file and you’re done.

function exclude_category_home( $query ) {
    if ( $query->is_home ) {
        $query->set( 'cat', '-5, -34' );
    }
    return $query;
}
 
add_filter( 'pre_get_posts', 'exclude_category_home' );

Thanks to WP Mayor for the code snippet!