Jon Weatherhead

AJAX Comments Refueled allows for pages to be cached without needing to invalidate on new comments, and is useful for upgrading the default comment system to not rely on page refreshes for replying to comments.
This plugin is a zero-dependency implementation. This means that it does not require jQuery.
Image by <a href="https://pixabay.com/users/geralt-9301/?utm_source=link-attribution" rel="nofollow ugc">Gerd Altmann</a> from Pixabay.
<h3>How To Use</h3>
Simply install and activate this plugin and it will work – there are no options to fuss over.

AJAX Comments Refueled

An all-AJAX drop-in for the stock comments system.

Mark Jaquith

When your posts get a lot of comments, performance can be a concern. The generation of the comment HTML and the delivery of all that HTML can slow down your page loads. This plugin has pages load without comments, and then uses a secondary AJAX request to pull down the comments. Navigating through the pages of comments is also handled via AJAX. On my test install with 100 comments per page, the <code>onload</code> event fires 2x faster. The HTML is generated by the server 6x faster. The HTML downloads 3x faster. The uncompressed size of the HTML is reduced by a factor of 17.
Initial development of this plugin was commissioned by Google — many thanks!

AJAX Comment Loading

Loads comments with a secondary AJAX request, including comment paging. Speeds initial loading of the page.

AJAX Comments Refueled vs AJAX Comment Loading