lehmannlabs

LehmannLabs WebP Optimizer is focused on one core goal: faster page load times.
The plugin converts your WordPress images to WebP and serves WebP files on the frontend whenever available. This reduces image payload and helps improve Core Web Vitals and user experience.
It was developed for WordPress websites built with Elementor and works well with typical Elementor image output (including image widgets, carousels, and background image use cases).
Unlike many plugins in this category, LehmannLabs WebP Optimizer is fully free to use, with no advertising, no tracking, and no premium upsells. Many competing plugins are either limited in their free version or are generally only available as paid products.
Tested with: 
– Elementor v3.35.6 
– Elementor Pro v3.35.1
Key benefits: 
– Faster frontend image delivery through WebP replacement 
– Completely free, with no ads and no paid upgrades 
– No feature limits in the free version and no paid-only core workflow 
– Optional auto-conversion on upload 
– Batch conversion for existing media 
– Safe fallback strategy and backup/restore tools 
– No external API calls, no tracking
Main features: 
– WebP generation for full-size and intermediate image sizes 
– Output modes: 
 – Picture mode (recommended): WebP source with fallback image 
 – Direct mode: direct URL/srcset replacement to WebP when available 
– Original image backup to <code>uploads/slimage-backup/YYYY/MM/</code> 
– Optional resize with configurable maximum edge length 
– Batch tools in wp-admin: 
 – Scan & Optimize 
 – Delete WebP Files 
 – Restore Originals 
– Site Health integration for WebP capability checks

LehmannLabs WebP Optimizer

Improve page speed in WordPress with a free WebP optimizer for Elementor workflows. No ads, no tracking, no paid upsells.

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.

LehmannLabs WebP Optimizer vs DZIEWA Media Converter — AVIF + WebP