Hinaloe

This plugin allow your site’s comment form makes ajax — non move/reload when user (including both subscriber, normal viewer, and admins too) post comment!
Most themes supports this plugin, but if your theme’s <code>class_form</code> have not <code>comment-form</code>, this plugin non supported.
And this plugin only can use for Pure WordPress Comment form. 
so, its not able to be used with like Jetpack comment form and other original/outside comment system/form.
Feature
<ul>
<li>post comment with ajax</li>
<li>Lite — this plugin only using a little of jQuery feature to modify DOM, and very tiny js & PHP code.</li>
</ul>
Require
You have to install <a href="https://wordpress.org/plugins/rest-api/" rel="ugc">WP REST API v2</a> to use this plugin if your site is running on WP 4.4-4.6.

ajax Post Comment

Post comment form on frontend tobe ajax using WP REST API Version.2

Brandon Hubbard

Hubbard Labs

This plugin enables logging of all calls to the WordPress REST API. You can view all logs from the WordPress Admin under API Log Pro.
<h3>WP-CLI Support</h3>
This plugin offers some basic wp-cli support. You can use the following command to delete all the logs in the db.
<pre><code>wp api-log-pro delete
</code></pre>

API Log Pro

A simple plugin to log WordPress Rest API Requests.

ajax Post Comment vs API Log Pro