Gagan Deep Singh

Sometimes you may want the images on your blog/site to be pixel perfect, while sometimes you may want them to be compressed to save space on the server.
This plugin allows you to select the quality of the thumbnail images generated by WordPress, as easy as that. Just go to Media Settings page and modify the Image Quality setting.
Plugin only works for new uploads, but in case you want to modify the thumbnails generated earlier, you can either use
<a href="https://wordpress.org/plugins/regenerate-thumbnails/" rel="ugc">Regenerate Thumbnails</a>
or if you are familiar with WP-CLI, then you can use this command to regenerate
<pre><code>wp media regenerate
</code></pre>
P.S. It does not change the quality of the original image that you upload, 
but only changes the quality of the thumbnails WordPress generates from that image.

Image Quality

Lets you adjust the quality of image thumbnails that WordPress generates.

Muhammad Umer Shahzad

Smart Image Optimizer is a powerful and lightweight plugin that:
<ul>
<li>Compresses uploaded images to reduce file size.</li>
<li>Converts images into modern formats like JPEG, PNG, AVIF, WebP, and more.</li>
<li>Retains visual quality using lossless or smart lossy compression.</li>
<li>Enables lazy loading to improve page speed.</li>
<li>Automatically optimizes images during upload.</li>
<li>Allows bulk optimization of existing media.</li>
</ul>
This plugin is ideal for bloggers, photographers, eCommerce stores, and all WordPress users aiming to improve performance and user experience.
<h3>Features</h3>
<ul>
<li>✅ Lossless and lossy compression options</li>
<li>✅ Format conversion: PNG ↔ JPEG, AVIF, WebP</li>
<li>✅ Automatic optimization on upload</li>
<li>✅ Bulk optimization of media library</li>
<li>✅ Lazy load for all images</li>
<li>✅ No third-party API required (works locally)</li>
</ul>
<h3>License</h3>
Smart Image Optimizer is open-source software licensed under the <a href="https://www.gnu.org/licenses/gpl-2.0.html" rel="nofollow ugc">GPLv2 or later</a>.

Smart Image Optimizer

Smart Image Optimizer compresses image sizes and converts them to modern formats like JPEG, PNG, AVIF, and more — for faster websites and better SEO.

Image Quality vs Smart Image Optimizer