How to remove “Category:” in the title of the article category

This issue is relevant if the title was added using the_archive_title();. To remove the extra phrase “Category:”, you need to use the hook:

add_filter( 'get_the_archive_title', 'lets_remove_name_category' );
function lets_remove_name_category( $title ){
	if ( is_category() ) {
		$title = single_cat_title( '', false );
	} elseif ( is_tag() ) {
		$title = single_tag_title( '', false );
	}
	return $title;
}

Add this code at the end of file functions.php of your theme.

This code allows you to remove any “Archives:”, “Category:”. It works for WooCommerce, which uses the same get_the_archive_title in the page-title:

add_filter( 'get_the_archive_title', function( $title ){
	return preg_replace('~^[^:]+: ~', '', $title );
});