Rafał Dziewa

DZIEWA Media Converter creates sidecar <code>.avif</code> and <code>.webp</code> files next to your originals (no replacement of JPG/PNG in the Media Library). On the front end it can rewrite <code><img></code> tags to <code><picture></code> so browsers pick AVIF/WebP when available. The plugin is entirely free to use — no license fees, no pro version, and no paid add-ons.
<h4>How it works</h4>
The plugin generates additional AVIF and/or WebP files beside every JPEG/PNG you upload. Originals are never touched or replaced — they remain in the Media Library and on disk as a safe fallback. The optional content filter detects <code><img></code> tags in your post content and wraps them in <code><picture></code> so modern browsers download the smaller AVIF/WebP version, while older browsers transparently fall back to JPG/PNG.
<h4>Conversion</h4>
<ul>
<li>AVIF + WebP, AVIF-only or WebP-only output modes. AVIF requires PHP GD built with AVIF support; the plugin auto-detects this on activation and gracefully falls back to WebP-only when AVIF is unavailable.</li>
<li>Configurable quality per format (independent AVIF and WebP quality sliders in settings).</li>
<li>Automatic conversion on upload — new attachments are converted in the background via WP-Cron or Action Scheduler (when available), so the upload screen never blocks.</li>
<li>Intermediate sizes (thumbnails) are optionally converted too, so every srcset variant has its own AVIF/WebP sidecar.</li>
</ul>
<h4>Existing media</h4>
<ul>
<li>Background queue processes already-uploaded images in configurable batches (default 20 files per run, range 5–200). You can scope the queue to a single uploads subfolder and/or a date range to avoid scanning the whole library at once.</li>
<li>Bulk action in the Media Library — select images and run Convert to AVIF/WebP from the bulk menu.</li>
<li>Per-attachment button — Media Library list, attachment edit screen and media modal each show a Convert to AVIF/WebP button next to live savings stats (before/after size, percentage saved per format).</li>
</ul>
<h4>Front end (content rewriting)</h4>
<ul>
<li>Optional <code><picture></code> rewrite in <code>the_content</code> and post thumbnails — browsers automatically pick the lightest format they support.</li>
<li>Lookup of attachment IDs from URLs is cached in the WordPress object cache (Redis/Memcached when available) and memoised per request, so heavy pages with many images stay fast.</li>
</ul>
<h4>Tools & admin UI</h4>
<ul>
<li>Cleanup tool — remove old generated <code>.avif</code> / <code>.webp</code> sidecars by age (30/60/90/120 days) and folder scope, with a per-folder picker.</li>
<li>Admin bar download — optional link on singular posts/pages to download the original JPG/PNG of the featured image (useful for social platforms that don’t accept AVIF/WebP).</li>
<li>Event log — last 100 events (errors, conversions, queue runs) visible on the settings page.</li>
<li>Three-option uninstall dialog — when removing the plugin you choose between Cancel, Remove (keep generated files) or Remove and delete files.</li>
</ul>
<h4>Privacy & dependencies</h4>
<ul>
<li>No external services, no remote calls, no tracking. Everything runs on your own server.</li>
<li>Requires PHP 8.3+ and PHP GD with WebP support (<code>imagewebp</code>). AVIF is optional.</li>
<li>Fully translated to Polish; English source strings ready for further translations via GlotPress.</li>
</ul>

DZIEWA Media Converter — AVIF + WebP

Converts JPEG/PNG to AVIF and WebP; rewrites content to <picture> with JPG/PNG fallback. Completely free, no paid version.

ImgHaste

Sociality

This WordPress plugin provides integration with our SaaS <a href="https://www.imghaste.com/" title="Image Service" rel="nofollow ugc">Image Service</a> 
By leveraging the Power of <a href="https://www.imghaste.com/blog/client-hints-explained" rel="nofollow ugc">Client Hints</a>.
We’ve chosen to integrate to WordPress via a Service Worker in order to provide best possible compatibility against 
Caching plugins (e.g. W3TC, WPSuper Cache, Elementor…) as well as images coming from your CSS files.
This way you won’t have to rewrite your URLS and lose your images SEO juice.
Nor you will get overcharged in case of a BOT crawl your website.
WHAT DOES THIS PLUGIN DO?
This plugin registers a Service Worker, providing Progressive Web App functionalities to your 
website in order to intercept your Images in order to automatically detect the best possible Image required by your end user.
Since we are speed monkeys, we need to say that the required javascript 
that will load on your page is 708 bytes gzipped. (without a k)
FEATURES OUT OF THE BOX:
<ul>
<li>White Label.</li>
<li>Automatic Integration.</li>
<li>Removes EXIF information.</li>
<li>Compatible with Page Builders.</li>
<li>Effective Connection Type Detection.</li>
<li>Quality drop on slow 3g or Save Data on.</li>
<li>Backup your images for Disaster recovery.</li>
<li>Works with images coming from CSS files.</li>
<li>Search Engines will grab the origin images.</li>
<li>Works with images coming from Ajax requests.</li>
<li>Compatible with Caching / Lazy Load plugins.</li>
<li>Backup your original image safely in the cloud.</li>
<li>Automatic AVIF Conversion based on browser support.</li>
<li>Automatic WebP Conversion based on browser support.</li>
<li>Progressive JPEGs & Interlaced PNGs as Net Gen fallback.</li>
</ul>
FULLY WHITE-LABEL
One of the reasons we decided to go with this approach is no other than SEO. 
Using Client Hints Combined with Service Worker will get you all the performance benefits 
for your end users without the SEO disadvantages that comes with the URL Rewrite.
WHY ITS IMPORTANT NOT TO CHANGE IMAGE URLS
In case you rewrite your image urls into something else all 
SEO juice from all image urls goes to the Vendor domain 
even if the urls contain a canonical name, they are still searchable using the vendor url.
PREREQUISITES
<ul>
<li>Your website runs https only</li>
<li>Your website doesn’t have a Service Worker already.</li>
</ul>
IMPORTANT
This plugin is not compatible with other plugins that registers a Service Worker. You’ll need to disable other plugins 
that registers a service worker on your website or use our <a href="https://www.imghaste.com/docs/" rel="nofollow ugc">Custom Integration Guide</a> and lose the white label feature.

AVIF, WebP, Image Optimization, CDN, Service Worker & Client Hints All in One

Speed up your website using cutting edge Image Service. Service Worker, Client Hints, WebP, 100% white labeled. NO URL Rewrite required.

DZIEWA Media Converter — AVIF + WebP vs AVIF, WebP, Image Optimization, CDN, Service Worker & Client Hints All in One