Rafał Dziewa

<p>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 <strong>entirely free to use</strong> — no license fees, no pro version, and no paid add-ons.</p>
<h4>How it works</h4>
<p>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.</p>
<h4>Conversion</h4>
<ul>
<li><strong>AVIF + WebP, AVIF-only or WebP-only</strong> 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><strong>Configurable quality</strong> per format (independent AVIF and WebP quality sliders in settings).</li>
<li><strong>Automatic conversion on upload</strong> — new attachments are converted in the background via WP-Cron or Action Scheduler (when available), so the upload screen never blocks.</li>
<li><strong>Intermediate sizes (thumbnails)</strong> are optionally converted too, so every srcset variant has its own AVIF/WebP sidecar.</li>
</ul>
<h4>Existing media</h4>
<ul>
<li><strong>Background queue</strong> 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><strong>Bulk action in the Media Library</strong> — select images and run <strong>Convert to AVIF/WebP</strong> from the bulk menu.</li>
<li><strong>Per-attachment button</strong> — Media Library list, attachment edit screen and media modal each show a <strong>Convert to AVIF/WebP</strong> 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><strong>Cleanup tool</strong> — 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><strong>Admin bar download</strong> — 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><strong>Event log</strong> — last 100 events (errors, conversions, queue runs) visible on the settings page.</li>
<li><strong>Three-option uninstall dialog</strong> — when removing the plugin you choose between <em>Cancel</em>, <em>Remove (keep generated files)</em> or <em>Remove and delete files</em>.</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.

aerqzs

<p>Sityn Image Optimizer integrates with the WordPress media uploader and optimizes image files in the browser before upload. It supports resizing, quality control, and conversion to WebP, JPG, PNG, and AVIF where supported.</p>
<p>The plugin processes selected images client-side, then passes the optimized files to the normal WordPress media upload flow.</p>


Sityn Image Optimizer

Optimizes image uploads in the browser before WordPress receives them.

DZIEWA Media Converter — AVIF + WebP vs Sityn Image Optimizer