Konrád Koller

Do you like to write long articles with many headers? Then this is the perfect plugin for you. This plugin will add a link next to your headers so your user can share your posts pointing to specific parts. Plus a smooth scroll script is also included which will make the overall experience even better.
The package contains a predefined style for Git-like link display but it is hardly recommend to change the style to fit your needs (and your design).
The plugin uses internal cache which may interfere with other cache plugins, if you experience anything strange feel free to contact the plugin author.

ONet Header Linkifier

For advanced users! Github-like header parser for your posts, pages and custom contents. Also lets you fetch TOC for any content.

pavlobondarchuk

Simple Sticky TOC automatically generates a sticky table of contents for single posts or pages by parsing <code><h2></code>, <code><h3></code>, and <code><h4></code> tags. It is lightweight, mobile-friendly, and works without jQuery.
Features: 
– Automatically detects and anchors h2–h4 headings 
– Sticky TOC with vertical layout on desktop 
– Sticky toggleable TOC on mobile 
– Built-in RTL support (positioning + layout) 
– Option to disable TOC on individual posts 
– Option to customize TOC layout from your theme 
– Auto-generated anchor IDs for headings 
– Clean CSS, pure JavaScript, no jQuery
<h3>Theme Override Support</h3>
To override the default markup or styles:
<ol>
<li>
Copy the default template files from the plugin:
<ul>
<li><code>frontend/partials/toc-template.php</code></li>
<li><code>assets/css/toc.css</code></li>
<li><code>assets/js/toc.js</code></li>
</ul>
</li>
<li>
Paste them into your theme inside the following folder:
<ul>
<li><code>your-theme/simple-sticky-toc/</code></li>
</ul>
</li>
</ol>
Supported override files:
<ul>
<li><code>simple-sticky-toc/toc-template.php</code> – custom TOC markup</li>
<li><code>simple-sticky-toc/toc.css</code> – custom styles</li>
<li><code>simple-sticky-toc/toc.js</code> – custom JS behavior</li>
</ul>

Simple Sticky TOC

Lightweight sticky table of contents for mobile and desktop. Automatically generates anchor links for h2–h4 headings. No jQuery.

ONet Header Linkifier vs Simple Sticky TOC