JoshuaPack

Why choose this plugin?
<ul>
<li>404 pages not working? </li>
<li>Would you like to have a custom 404 page? </li>
<li>Would you like the 404 page to be a static page? </li>
<li>Do you need to have a WordPress CMS page as your 404 page?</li>
</ul>
This plugin does it!
This a rebel plugin that does not use WordPress’s 404 hook. It was developed for themes or plugins that cause issues with the hook itself.
For more information see FAQ page.

HTD 404

This plugin will simply allow you to point to a page to serve up if you get a 404 error. Also it marks it as 404.

stooit

QuantCDN is a CDN engineered specifically for the static web. This plugin acts as a static site generator, letting you easily push a static copy of your entire WordPress site with a single click. Any ongoing content change is automatically pushed, ensuring your static site in the QuantCDN edge is always kept in sync.
Full support for: 
* Pages and Posts 
* Homepages (static or lists), including pagination 
* Archives (including pagination) 
* 404 error page 
* Custom routes 
* Tags and Categories (including pagination) 
* Attached images & media, CSS, Javascript 
* Custom post and page types
The QuantCDN platform has integrated support for both <a href="https://docs.quantcdn.io/docs/dashboard/forms" rel="nofollow ugc">forms</a> and <a href="https://docs.quantcdn.io/docs/dashboard/search" rel="nofollow ugc">search</a>.
Requires a <a href="https://www.quantcdn.io" rel="nofollow ugc">QuantCDN account</a>
<h3>WP-CLI support</h3>
WP-CLI is a command line tool to interface with WordPress. It is the recommended way of initially seeding your WordPress site in Quant, and provides vast performance improvements over using the UI.
This is largely due to the ability to run the seed process with concurrency, which can immediately give a 10x performance boost (or greater) when compared to using the UI.
<ul>
<li>Use <code>wp quant info</code> to view queue status</li>
<li>Use <code>wp quant reset_queue <queue_name></code> to reset a queue</li>
<li>Use <code>wp quant process_queue <queue_name|all> --threads=10</code> to push content to Quant</li>
</ul>

QuantCDN

QuantCDN static site generator and edge integration. Push a static export of your Wordpress site with ease.

HTD 404 vs QuantCDN