Mike Bricknell-Barlow

This plugin helps to increase site speed, and helps to improve scores in Google’s Pagespeed Insights tool by addressing the common recommendation “Serve next-gen image formats”.
For the best speeds, Google recommends using new image formats such as .webp, which offer smaller file sizes than common formats such as .jpg or .png with no visible loss in quality. However, not all internet browsers support the .wepb image format, so only using that format would result in broken images in older browsers.
This plugin addresses that problem, and allows your site to use .webp images when it can. This plugin will convert images from .jpg or .png automatically, and save .webp versions of the image alongside the original. When a user visits the site in a compatible browser, they will be shown the .webp versions of all images, making your site load faster and improving your scores in Google Pagespeed Insights. Users on older browsers that aren’t compatible with .webp images will be shown the .jpg or .png versions of the images instead.
When first installing the plugin, run the Bulk Converter to convert all your existing images. See the Installation section for instructions.
After installation, any .jpg or .png image uploaded to the Media Library will be automatically converted.
<h3>Settings</h3>
<ul>
<li>
Conversion quality – Controls the level of compression on the generated .webp images. The lower the value, the smaller the file size of the generated images, but the more chance there is of a visual degradation of quality. The quality value to be entered is a percentage – by default, this is set at 80%. Most users won’t need to change this.
</li>
<li>
HTML Output Buffering – This allows the plugin to perform a find-and-replace on the HTML that WordPress has generated for output to the browser to replace image tags. This tends to perform the image tag replacement more reliably, but can cause issues with some themes. Users are advised to have this setting turned on, but they should check that the site is displaying as it should, and turn this option off if any issues arise.
</li>
<li>
Exclude pages from HTML output buffering – To specify pages that should be excluded from the HTML Output Buffering settings
</li>
<li>
Lazy loading – This improves the site speed further by not loading images that are further down the page until the user has scrolled down to them. This saves time downloading images that the user hasn’t got to yet, or might not get to at all. Users are advised to have this setting turned on, but they should check that the site is displaying as it should, and turn this option off if any issues arise.
</li>
<li>
Exclude image classes from lazy-loading – To specify images, by class name, that should not have the lazy-loading applied
</li>
</ul>
<h3>Developers</h3>
If using Simple Webp Images with your custom themes or plugins, there’s a couple of filters you can use, as below.
<ul>
<li><code>simple-webp-images-exclude-from-output-buffering</code> filter</li>
</ul>
Use this to exclude pages or posts from the HTML output buffering via <code>apply_filters</code>, using any critera you need. Call the filter, run any checks you need, and return ‘true’ to exclude the current page or post from the buffering. 
Example:
<pre><code>apply_filters( 'simple-webp-images-exclude-from-output-buffering', 'exclude_page_with_id_100_from_output_buffering' );
function exclude_page_with_id_100_from_output_buffering( $is_excluded ) {
 if( get_the_id() == 100 ) {
 return true;
 }

 return false;
}
</code></pre>
The example code could be placed in your <code>functions.php</code> file.
<ul>
<li><code>simple-webp-images-exclude-from-lazy-loading</code> filter</li>
</ul>
Use this to exclude pages or posts from the image lazy loading via <code>apply_filters</code>, using any critera you need. Call the filter, run any checks you need, and return ‘true’ to exclude the current page or post from the lazy loading. 
Example:
<pre><code>apply_filters( 'simple-webp-images-exclude-from-lazy-loading', 'exclude_page_with_id_100_from_lazy_loading' );
function exclude_page_with_id_100_from_lazy_loading( $is_excluded ) {
 if( get_the_id() == 100 ) {
 return true;
 }

 return false;
}
</code></pre>
The example code could be placed in your <code>functions.php</code> file.

Simple Webp Images

Generates webp images from uploaded images, and outputs webp images in content in compatible browsers. Optionally provides lazy-load functionality.

saguya

Welcome to Henkan (Japanese for “conversion”) — your lightweight, high-performance solution for next-generation image optimization in WordPress!
Slow loading times and heavy images are a thing of the past. Henkan seamlessly integrates into your WordPress dashboard, silently converting your standard JPEGs and PNGs into highly optimized WebP or AVIF files. Boost your Core Web Vitals, improve your SEO rankings, and save massive amounts of server bandwidth without sacrificing an ounce of image quality.
<h3>✨ Why choose Henkan?</h3>
Most image optimizers rely on slow PHP processing or expensive cloud APIs with monthly limits. Henkan is built differently: It prioritizes native OS binaries (<code>cwebp</code>, <code>avifenc</code>) to process images blazingly fast directly on your own server, completely free and without any restrictions.
<h3>🚀 Powerful Features</h3>
<ul>
<li>Next-Gen Formats: Instantly convert images to WebP and AVIF formats.</li>
<li>Zero-Config Auto-Conversion: New images are optimized silently in the background the moment you upload them.</li>
<li>1-Click Bulk Optimization: Got a massive existing media library? Process thousands of images with a single click in our beautiful, modern dashboard.</li>
<li>Smart Fallbacks: Uses ultra-fast <code>exec()</code> binaries when available, falling back to GD or ImageMagick seamlessly if needed.</li>
<li>Cache Auto-Clear: Fully compatible with WP Rocket, W3 Total Cache, Autoptimize, and LiteSpeed Cache. Conversions automatically trigger a cache purge.</li>
<li>Frontend Delivery: Automatically serves the optimized images to compatible browsers using modern HTML <code><picture></code> tags or Nginx/Apache rewrites.</li>
<li>WP-CLI Power: Built-in commands (<code>wp henkan convert</code>) for sysadmins to process massive libraries directly from the terminal without PHP timeouts.</li>
<li>Global Ready: 100% translation-ready. Shipped with English, German (<code>de_DE</code>), and Japanese (<code>ja</code>) out of the box.</li>
</ul>
<h3>🛠️ System Requirements</h3>
To unleash the full speed of Henkan, we recommend: 
* WordPress: 6.0 or higher 
* PHP: 7.4 or higher 
* For WebP: <code>cwebp</code> installed on the server (recommended) OR PHP <code>GD</code> extension with WebP support. 
* For AVIF: <code>avifenc</code> or <code>ImageMagick</code> (magick/convert) installed OR PHP <code>GD</code> extension with AVIF support.

Henkan – WebP & AVIF Converter

Henkan is a high-performance plugin that automatically converts your media library images to next-generation formats like WebP and AVIF.

Simple Webp Images vs Henkan – WebP & AVIF Converter