tempranova

This is a simple plugin that uses AJAX to load comments, converting the “Newer/Older Comments” button into a button that loads more comments instantly.
This plugin also paginates nested replies. You can customize styling in whatever way you choose.
Using Settings > Comment Load More, user can set desired pagination (currently both comments and replies have the same number).

Comment Load More

This plugin allows you to load more comments instantly via a button push (AJAX), instead of pagination that reloads the page.

Callum Silcock

Instead of taking you to a different page (wp-comments-post.php) which does not redirect this script just ads some quick text above your form to let your users know if there was an error or if the comment was posted successfully (if successful it then clears the form).
There are a few plugins that do a simliar thing to this already but unfortunately most of the current AJAX commenting solutions I found in the plugin directory havent been updated in years or just didn’t work, so following on from many “how to AJAX’ify your wordpress comments” blog posts I thought i’d make a simple plugin instead (which means no coding knowledge required).
The script chooses the #commentform div/form as this is default.
Ill update this plugin when needed but I do not offer any warranty or support for it.

Silk AJAX Comments

The default wordpress comments system is awful when it comes to handling errors, this fixes this issue with some simple AJAX.

Comment Load More vs Silk AJAX Comments