Limit post revisions

// Keep at most 5 revisions per post. Post types without revisions stay at 0.
add_filter(
	'wp_revisions_to_keep',
	function ( $num ) {
		$max = 5;
		return ( $num < 0 || $num > $max ) ? $max : $num;
	}
);

What it does

WordPress keeps every saved version of a post as a revision, with no limit. Posts edited often can build up hundreds of revisions and bloat your database.

This snippet keeps the 5 newest revisions for each post. Change $max to keep more or fewer. If revisions are already off, or wp-config.php sets a lower limit, that setting stays.

Good to know

• Extra revisions are deleted the next time each post is saved, not straight away.