Arya Dhiratara

ThinkWeb

A lightweight yet powerful image, iframe, and video optimization plugin. Lazy load, preload, and more. No jquery dependency.
<h3>Features</h3>
<ul>
<li>Lazy Load – Lazy loading images, iframes, and videos, using the high performant <code>lazysizes.js</code>. No jquery dependency.</li>
<li>Preload Featured Images – Automatically preloading featured image from common page/post (homepage, pages except homepage, single post, and woocommerce single product pages).</li>
<li>Use CDN for Images – HTML rewrite if you want to serve images from your favorite CDN.</li>
<li>Add Missing Image Dimensions – Add missing width and height attributes from your images.</li>
</ul>
New (since 1.1.1)
<ul>
<li>Add <code>no-lazy</code> and <code>skip-lazy</code> class as default exclude class for lazyloading images.</li>
<li>Enable <code>loading eager</code> to also target <code>no-lazy</code> and <code>skip-lazy</code> class.</li>
<li>Automatically exclude featured image (add <code>no-lazy</code> class) from lazyloading if <code>Preload Featured Images</code> feature is enabled (useful to avoid <code>Largest Contentful Paint image was lazily loaded</code> warning in Google Pagespeed Insights ).</li>
<li>Add <code>webp</code> extension to CDN HTML rewrite regex.</li>
</ul>
New (since 1.0.7)
<ul>
<li>We changed the lazy load library from lozad.js to lazysizes.js.</li>
<li>Add field to modify lazysize default configuration. Read the <a href="https://github.com/aFarkas/lazysizes/#js-api---options" rel="nofollow ugc">docs</a>.</li>
<li>Add fields to specify width and height fallback value if the Add Missing Image Dimensions feature failed to get the actual image dimension.</li>
</ul>
New (since 1.0.3)
<ul>
<li>Lazy load CSS Background Images – Load faster by lazy loading background images from the CSS <code>background-image</code> property. Tested and works well on CSS background image from <code>GenerateBlocks</code>, <code>Elementor</code>, and <code>Oxygen Builder</code>.</li>
<li>Noscript Fallback – Extra option to use <noscript> fallback for lazy images and iframes.</li>
<li>Add Loading Eager – Extra option to Automatically add <code>loading=eager</code> to the lazy load excluded list.</li>
</ul>
This plugin only adds 1 extra row in your database. And it will self delete upon uninstalation.
<h3>About Lazysizes</h3>
Lazysizes is highly performant lazy load library, written by Alexander Farkas in pure JS with no dependencies.
Taken from lazysize’s github description: 
High performance and SEO friendly lazy loader for images (responsive and normal), iframes and more, that detects any visibility changes triggered through user interaction, CSS or JavaScript without configuration.
<h3>Optimize More!</h3>
Need to optimize more? Try our <a href="https://thinkweb.dev/service/speed-optimization/" rel="nofollow ugc">WordPress Speed Optimization’s Service</a>.
<h3>Other USEFUL PLUGINS TO OPTIMIZE YOUR SITE’S SPEED:</h3>
<ul>
<li>
<a href="https://wordpress.org/plugins/optimize-more/" rel="ugc">Optimize More!</a> – Selectively Optimize your CSS/JS Delivery: Load CSS Asynchronously, Delay CSS and JavaScripts until User Interaction, Preload Critical CSS and JavaScripts, and Remove Unused CSS and JavaScripts Files.
</li>
<li>
<a href="https://wordpress.org/plugins/lazyload-preload-and-more/" rel="ugc">Lazyload, Preload, and more!</a> – A simplified version of this plugin. The plugin size is only around 14kb zipped. Without UI for settings, but you can customize the settings using filters. 
The default configuration is the best for optimizing images and other media files to speed up your site (just install and activate it and you’re good to go):
<ul>
<li>lazyload your below the fold images/iframes/videos,</li>
<li>preload your featured images,</li>
<li>and add loading=”eager” to your featured image and all images that have <code>no-lazy</code> or <code>skip-lazy</code> class.</li>
</ul>
</li>
</ul>
<h3>Other USEFUL PLUGIN:</h3>
<ul>
<li>
<a href="https://wordpress.org/plugins/shop-extra/" rel="ugc">Shop Extra</a> – A lightweight plugin to optimize your WooCommerce & Business site: Floating WhatsApp Chat Widget (can be use without WooCommerce), WhatsApp Order Button for WooCommrece, Hide/Disable WooCommerce Elements, WooCommerce Strings Translations, and many more.
</li>
<li>
<a href="https://wordpress.org/plugins/animate-on-scroll/" rel="ugc">Animate on Scroll</a> – Animate any Elements on scroll using the popular AOS JS library simply by adding class names. This plugin helps you integrate easily with AOS JS library to add any AOS animations to WordPress. Simply add the desired AOS animation to your element class name with “aos-” prefix and the plugin will add the corresponding aos attribute to the element tag.
</li>
</ul>

Optimize More! – Images

A lightweight yet powerful image, iframe, and video optimization plugin. Lazy load, preload, and more. No jquery dependency.

Justin Downey

This plugin adds the <code>loading</code> attribute to IMG tags found when filtering <code>the_content()</code> to support native image lazy loading.
For more information about lazy loading images using this new native browser image attribute, check out this article: <a href="https://addyosmani.com/blog/lazy-loading/" rel="nofollow ugc">https://addyosmani.com/blog/lazy-loading/</a> and for a little more depth into what we’re doing here, check out our <a href="https://jdmdig.it/30nXp7h" rel="nofollow ugc">explainer post</a>.
Historically, to limit the impact offscreen images have on page load times, developers have needed to use a JavaScript library (like <a href="https://github.com/aFarkas/lazysizes" rel="nofollow ugc">LazySizes</a> or <a href="https://www.andreaverlicchi.eu/lazyload/" rel="nofollow ugc">Vanilla-LazyLoad</a>) in order to defer fetching these images until a user scrolls near them. What if the browser could avoid loading these offscreen images for you?
The <code>loading</code> attribute instructs a browser to defer loading offscreen images until users scroll near them. It comes in three flavors: eager, auto, and lazy. Install this plugin and you can set the first image’s loading attribute and the loading attribute for all the subsequent images sent through <code>the_content()</code> in the plugin’s settings page.
Simple is Beautiful
There is no JavaScript or CSS included in the plugin. It just works in browsers that support the new <code>loading</code> image attribute.
For browsers that don’t support this new image loading attribute, that’s ok. You can still use whatever JavaScript-based image lazy loader you want as a fallback until browser support becomes a little more mainstream.

Native Image Lazy Loading

Automatically add the new loading attribute to images within your content to support native image lazy loading.

Optimize More! – Images vs Native Image Lazy Loading