mabujo

Featured Image Sharpen Up makes a tiny version of your featured post image and places it in the head of the page. 
As you scroll down the page, some JavaScript lazy loads the featured images in the background and replaces the tiny images as the full images are loaded.
You may have seen a similar effect used for images on medium.com.
Created on WordPress 4.4, but should work on earlier versions. 
Tested working on all Twenty Sixteen, Twenty Fifteen, Twenty Fourteen, Twenty Thirteen, Twenty Twelve and Twenty Eleven themes. Should work on other themes, but may need CSS adjustments, depending on theme handling of featured images.
Uses jQuery.Lazy(); (http://jquery.eisbehr.de/lazy/) and Hugh Lashbrooke’s plugin template (https://github.com/hlashbrooke/WordPress-Plugin-Template)
Plugin page : <a href="https://mabujo.com/blog/featured-image-sharpen-up-wordpress-plugin/" rel="nofollow ugc">Featured Image Sharpen Up plugin @ mabujo</a>

Featured Image Sharpen Up

This plugin helps increase the page loading speed of your site by replacing featured post images with a small inline image, and lazy loading the full  …

ShortPixel

<h3>🚀 The Ultimate Caching and Speed Improvement Plugin for WordPress</h3>
Have you ever wished your website scored 90+ on Google PageSpeed Insights, GTMetrix and other website performance analysis tools? 
And achieve that without the need to pay expensive fees to consultants or learn a lot of advanced technical stuff?
⚡ <a href="https://fastpixel.io/?utm_source=wp-repository&utm_medium=link" rel="nofollow ugc">FastPixel</a> automatically integrates all the latest technical enhancements, such as Page Caching, HTML/CSS/JS minification, DNS prefetching and preloading, Critical CSS, ShortPixel’s <a href="https://shortpixel.com/blog/introducing-smartcompress/?/?utm_source=wp-repository&utm_medium=link" rel="nofollow ugc">Smart Image Optimization</a>, adaptive images, background image scaling and optimization, HTTP/2 support, fonts loading optimization, caching, a global CDN, and Core Web Vitals, within an easy-to-use, 1-minute-setup interface.
<iframe loading="lazy" title="FastPixel Ad" width="750" height="422" src="https://www.youtube.com/embed/6UbWASU8RNw?feature=oembed" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share" referrerpolicy="strict-origin-when-cross-origin" allowfullscreen></iframe>
<h3>🎬 Ready for a Quick TEST of our Speed Optimization Tool?</h3>
There is no need to install our plugin to run a test. 
You can test FastPixel live on a <a href="https://tastewp.com/template/FastPixel" rel="nofollow ugc">sandbox website@TasteWP</a> or you can quickly assess how <a href="https://fastpixel.io/" rel="nofollow ugc">FastPixel</a> can optimize your website by conducting a test. Simply use <a href="https://test.fastpixel.io/" rel="nofollow ugc">this test page</a>, and we will apply all optimizations to a copy of your website. 
This way, you can easily evaluate the substantial speed improvements it can achieve using the most widely recognized website performance analysis tools.
<h3>💡 Why choose FastPixel Caching plugin?</h3>
<ul>
<li>Website Performance Boost: Just activate the plugin and within seconds the optimized webpages will start to be served.</li>
<li>Lower the CPU/RAM Impact: Using the plugin will reduce the impact on the resources used by your website. All the CPU intensive processing is done in the cloud and resulting pages will generally be served from a cached version and the optimized images from the CDN.</li>
<li>Automated Core Web Vitals Optimization: FastPixel takes care of all technical aspects automatically.</li>
<li>Smart Cache Warmup/Update: The cache warmup and update are taken care of automatically in a smart way. Pages are cached as they are visited and also updated if you update the content.</li>
<li>Critical CSS: CCSS is automatically generated for each page for lightning-fast page loads.</li>
<li>CSS/JS Processing: CSS/JS files are combined and also minified and compressed before they are served from our CDN.</li>
<li>HTML Optimization: A single, highly optimized HTML file is generated, adaptively serving the ideal webpage based on the visitor’s viewport or device (e.g., mobile, tablet, laptop).</li>
<li>DNS Preconnects: Accelerates resource fetching, reduces the access time to external resources.</li>
<li>Font Processing: All the techniques to accelerate the processing and delivery of fonts are employed, e.g. font subsetting, font loading control, font compression, font embedding (lower CLS result).</li>
<li>Image Resizing & Optimization: Images are automatically resized to fit their placeholders, optimized, and delivered through the ShortPixel CDN.</li>
<li>Automatic Next-Gen Images Delivery: Based on the visitor’s browser capabilities, original JPG, PNG, or GIF images are converted to and served as WebP or AVIF when supported. For browsers without support, the original format is provided.</li>
</ul>
<h3>🌟 Happy users that use our plugin</h3>
If you’re satisfied with the test, just search for “FastPixel” in your WordPress Dashboard > Plugins, install the plugin and see for yourself how much faster your site becomes.
<blockquote>
Testimonials: 
 ★★★★★ It’s as fast as it says in the title! <a href="https://wordpress.org/support/topic/its-as-fast-as-it-says-in-the-title/" rel="ugc">liquidsnake2021</a> 
 ★★★★★ I was a tester and now I`m a happy user <a href="https://wordpress.org/support/topic/i-have-been-tester-and-now-happy-user/" rel="ugc">jppl</a> 
 ★★★★★ This plugin’s fast and easy to set up—I barely have to configure anything <a href="https://wordpress.org/support/topic/this-plugin-works-as-described/" rel="ugc">fajrisp</a> 
 ★★★★★ Works really well! <a href="https://wordpress.org/support/topic/works-really-well-264/" rel="ugc">touto</a> 
 ★★★★★ One of the best tools! <a href="https://wordpress.org/support/topic/one-of-the-best-tools-for-that/" rel="ugc">torsten3d</a> 
 ★★★★★ Super easy to install and worked out of the box <a href="https://wordpress.org/support/topic/well-this-was-easy-moving-from-wp-rocket/" rel="ugc">diffler</a> 
 <a href="https://wordpress.org/support/plugin/fastpixel-website-accelerator/reviews/?filter=5" rel="ugc">more testimonials</a>
</blockquote>
<h3>📩 Additional questions</h3>
If you have more questions, technical or otherwise, please refer to our FAQ section below, our <a href="https://fastpixel.io/docs/" rel="nofollow ugc">docs</a> or <a href="https://fastpixel.io/#contact" rel="nofollow ugc">contact us</a>. 
We typically respond within 15 minutes.

FastPixel Cache – Optimize Page Speed: Compress Images, Minify, Clean Database & CDN

Optimize Core Web Vitals and PageSpeed with advanced caching, image compression, lazy loading, critical CSS, and CDN – the ultimate performance tool.

Featured Image Sharpen Up vs FastPixel Cache – Optimize Page Speed: Compress Images, Minify, Clean Database & CDN