Jamie Dąbrowiecki

Headingo is a lightweight utility plugin that allows administrators to control which heading levels are available in the editor toolbar. This tool only works for websites using the Classic Editor.
These settings are applied to all users with editing permissions.
The configurable heading levels are:
<ul>
<li>Heading 1</li>
<li>Heading 2</li>
<li>Heading 3</li>
<li>Heading 4</li>
<li>Heading 5</li>
<li>Heading 6</li>
<li>Preformatted</li>
</ul>
This is especially useful for removing the Heading 1 (H1) option to prevent editors from mistakenly selecting it, as well as removing heading levels which are not required on your website.
This plugin is intended for websites that rely on the Classic Editor editing experience. It does not attempt to modify the Block Editor (Gutenberg), where heading availability is governed by editor and theme configuration (theme.json) by design. The Classic Editor plugin is required for this plugin to work (or a theme that allows you to switch to the Classic Editor without the plugin).
<h3>Classic Editor</h3>
The Classic Editor (TinyMCE) is fully supported. Selected heading levels and Preformatted can be hidden from the formatting dropdown while remaining available via keyboard shortcuts or pasted HTML. The Paragraph option is always available and cannot be toggled.
<h3>Block Editor (Gutenberg)</h3>
This plugin does not control heading levels in the Block Editor. Gutenberg does not currently provide a reliable API for plugins to override available heading levels, as these are controlled by editor and theme settings.

Headingo

Choose which heading levels are visible in the Classic Editor toolbar.

ayushag96

Make nice and noticable boxes like info box, alert box, success box, warning box etc. in your posts using shortcodes. These boxes are very easy to add and very attractive.
Special Features:
<ul>
<li>Close button for the Notice Boxes which can close the box on click</li>
<li>Easily make text in the box center aligned.</li>
<li>Various kinds of boxes for different messages</li>
<li>Add notice boxes using shortcodes (very easy)</li>
<li>A special page on your wordpress dashboard with all the help and reference material you need</li>
</ul>
For more information see Screenshots and FAQ!

Notice Boxes with Shortcodes

This plugin allows you to make notice boxes (styled content boxes of different colors) to display different messages via shortcodes.

Headingo vs Notice Boxes with Shortcodes