John Dalesandro

Head Trimmer gives you granular control over what WordPress automatically outputs in the HEAD element of every page. Each option is independent; enable only the removals that make sense for your site.
Removing unnecessary HEAD elements reduces page weight, eliminates potential security signatures such as the WordPress version number, and keeps your generated source code clean.
All settings are opt-in. Nothing is removed until you enable it on the Admin → Settings → Head Trimmer screen.
Removal options include:
<ul>
<li>WordPress Version (generator meta tag)</li>
<li>WordPress Version from Script and Style URLs</li>
<li>All Other Version Signatures from Script and Style URLs</li>
<li>Shortlink</li>
<li>Shortlink from HTTP Response Headers</li>
<li>Canonical</li>
<li>Relational Links for Posts Adjacent to Current Post</li>
<li>RSS Feeds (removes head links and disables feed endpoints)</li>
<li>Really Simple Discovery Link for xmlrpc (rsd_link)</li>
<li>Windows Live Writer Manifest File Link (wlwmanifest_link)</li>
<li>oEmbed Discovery Links</li>
<li>REST API Link and REST API Link Header</li>
<li>Emoji Support</li>
<li>Global Styles and SVG Filters (duotone filters)</li>
<li>Gutenberg Block CSS Styles (or optionally set ‘should_load_separate_core_block_assets’ to load block styles only when needed)</li>
<li>Classic Theme CSS Styles (classic-theme-styles)</li>
<li>DNS Prefetch for //s.w.org</li>
<li>DNS Prefetch for Google Fonts //fonts.googleapis.com</li>
<li>jQuery</li>
<li>JavaScript Import Map (added in WordPress 6.5)</li>
<li>Interactivity API (added in WordPress 6.5)</li>
<li>Image Auto Sizes Styles (added in WordPress 6.7)</li>
<li>Speculation Rules (added in WordPress 6.8)</li>
<li>Comment Reply Script (loads only on singular posts and pages where comments are open)</li>
</ul>

Head Trimmer

Selectively remove WordPress version information, feeds, shortlinks, emoji support, scripts, styles, and other automatically generated extras from the …

stanton119

WordPress HTML allows you to add custom HTML to both the post/page BODY and the HEAD tags from the page editor.
When copying HTML into the WordPress editor it adds spurious tags which break various elements and corrupt the HTML. By saving the HTML in the custom fields dialogue the exact HTML will be output to your post/page.
Also if you have a single page which requires an extra javascript library or style sheet you normally have to add it through your themes php files. Updating the theme files can be a pain; we normally have to set up an exception for that individual page and load it there. As this information is not available when we are editing the actual pages in the WordPress editor it is quite obstructive.
With WordPress HTML, we can add the library or stylesheet directly to the post/page head without the need to change the theme files. And importantly, all from within the WordPress editor for that page.
Example libraries: 
jQuery, ChartJS, D3js, Highcharts, Prototype
More details: <a href="http://www.richard-stanton.com/wordpress/wordpress-html/" rel="nofollow ugc">WordPress HTML</a>
Code: <a href="https://github.com/stanton119/WordPress-HTML-Plugin" rel="nofollow ugc">GitHub</a>

WordPress HTML

Add raw HTML to any post/page, without the Wordpress editor breaking it.

Head Trimmer vs WordPress HTML