Jeff Starr

This plugin overrides WordPress “automatically close comments” option on a per-post basis. So you can leave comments open on any post(s).
👉 Want to keep comments open on a few old posts? This plugin is for you.
👉 Uses only 4KB of code, so super lightweight, fast, and effective.
Features
<ul>
<li>Clean, secure code</li>
<li>Written according to the WP API</li>
<li>Simple, lightweight, and flexible</li>
<li>Localized and translation ready</li>
<li>Cleans up after itself when uninstalled</li>
</ul>
How it works
In the WordPress Discussion Settings, there is an option called “Automatically close comments on posts older than” whatever specified number of days. When this setting is enabled, comments will be disabled on any posts that are past the deadline, whatever “x” number of days.
What WordPress is missing is a simple way to override that global option on a per-post basis. That’s exactly what this plugin does.
For any post that is past the comment deadline, this plugin will display a small meta box on the “Edit Post” screen for each post. There you can check the box to enable comments on the post. Comments will then remain open for that post indefinitely, until the box is unchecked or the plugin is uninstalled. Check out the screenshot below to get a better idea.
For more details about how it works, visit the <a href="https://wordpress.org/plugins/override-comment-options/#installation" rel="ugc">Installation docs</a>.
Privacy
This plugin does not collect or store any user data. It does not set any cookies, and it does not connect to any third-party locations. Thus, this plugin does not affect user privacy in any way.
Override Comment Options is developed and maintained by <a href="https://x.com/perishable" rel="nofollow ugc">Jeff Starr</a>, 15-year <a href="https://plugin-planet.com/" rel="nofollow ugc">WordPress developer</a> and <a href="https://books.perishablepress.com/" rel="nofollow ugc">book author</a>.

Override Comment Options

Does exactly what it's supposed to do

Enables per-post override of "Automatically close comments on posts older than" option in the WP Discussion Settings.

wpsimpletools

Completely disables comments functionality from backend and frontend: 
* Hides existing comments 
* Close comments on the front-end 
* Disable support for comments, trackbacks and ping 
* Redirects any user trying to access comments page 
* Removes comments metabox from dashboard 
* Removes comments links from admin bar 
* Removes comments page in menu 
* Completely disables comments API

Disable Comments

The type of plugin I just love... does exactly what it says, no configuration necessary, source readable and understandable in minutes.

Simple, effective, no config ✅

Completely disables comments functionality from backend and frontend. Just install it, nothing to configure!

Override Comment Options vs Disable Comments