The comments_per_page filter allows you to define the number of comments to list per page in the comments list table.

It is evaluated in:

• WP_Comments_List_Table::get_per_page() in the wp-admin/includes/class-wp-comments-list-table.php file
• WP_Screen::render_per_page_options() in the wp-admin/includes/screen.php file

comments_per_page accepts 2 arguments:

1. int $comments_per_page The number of comments to list per page.
2. string $comment_status The comment status name. Default is ‘all’.

Example:

I don’t know about you, but when I go to clean out spam comments, it’s irritating to have that extra step of upping the comments per page — the default is 20 — just so I can bulk-delete them faster. The following example raises the comments-per-page amount only when you’re in the ‘Spam’ filtered view.

	<?php
	/**
	* Increase comments-per-page limit when viewing spam comments
	*
	* @see WP_Comments_List_Table::get_per_page(), WP_Screen::render_per_page_options()
	*
	* @param int $comments_per_page The number of comments to list per page.
	* @param string $comment_status The current comment status view. Default is 'all'.
	*
	* @return int The filtered number of comments to list per page.
	*/
	function wpdocs_delete_more_spam_comments( $comments_per_page, $comment_status ) {
	if ( 'spam' == $comment_status )
	$comments_per_page = 50;
	return $comments_per_page;
	}
	add_filter( 'comments_per_page', 'wpdocs_delete_more_spam_comments', 10, 2 );

view raw comments_per_page.php hosted with by GitHub

View the code example on Gist.