Yephy

JZB Image Auto AVIF is an image optimization engine that helps WordPress users automatically generate compressed AVIF and WebP images. It does this without altering the original media library files, utilizing an independent cache directory architecture to safely serve optimized images to browsers.
<h3>Core Features:</h3>
<ul>
<li>Non-destructive Cache: Generated AVIF and WebP files are stored in a separate <code>wp-content/uploads/jzb-image-auto-avif/</code> directory. Uninstalling the plugin instantly restores your original media library.</li>
<li>Dual-Core Compression: Configure distinct quality settings for AVIF and WebP formats. Supports fine-grained adjustment and switching between lossy and lossless modes.</li>
<li>HTML Output Buffering: Dynamically replaces image links in the front-end HTML source without relying on <code>.htaccess</code> or <code>nginx.conf</code> rewrite rules.</li>
<li>Native Intervention Control: Provides toggles to prevent WordPress from generating unnecessary multi-size thumbnails or applying <code>-scaled</code> changes, helping to save server disk space.</li>
<li>Media Library Controls: Includes AJAX buttons in the Media Library list view to generate AVIF/WebP for individual old images or cleanly delete legacy thumbnails.</li>
<li>Dynamic Loading Thresholds: Recommends sizing configurations based on your server’s available CPU cores and RAM to prevent server timeouts during heavy image conversion.</li>
</ul>

JZB Image Auto AVIF

Automatically optimize WordPress images to AVIF and WebP using an independent mirror cache and safe output buffering.

webwonderland

Web Wonderland SEO Image Optimiser helps you improve image performance and accessibility without breaking your theme.
The plugin can:
<ul>
<li>Convert images to modern formats (WebP/AVIF)</li>
<li>Serve WebP automatically on the front-end</li>
<li>Generate <code><picture></code> markup for improved Core Web Vitals</li>
<li>(Optional) Generate AI-based captions, alt text and titles in the same language as the WordPress site language</li>
<li>Integrate with Gutenberg, classic themes, Elementor, WPBakery, etc.</li>
<li>Use server-level rewriting or markup-based delivery modes</li>
<li>Restore original images at any time</li>
</ul>
This is a third-party plugin developed by Web Wonderland. 
It is not affiliated with or endorsed by WordPress, Elementor or WPBakery.
<h3>Local vs Cloud processing</h3>
The optimiser can work in two ways:
Local processing (always available) 
Runs entirely on your own server.
<ul>
<li>Unlimited WebP and AVIF generation (subject to your servers capabilities)</li>
<li>No monthly conversion caps</li>
<li>No api key required</li>
<li>Uses your own CPU and disk I/O</li>
</ul>
Cloud/API processing (api key required) 
Offloads heavy image work to the Web Wonderland Image API.
<ul>
<li>Uses a remote worker to generate WebP/AVIF for originals and all sizes</li>
<li>Reduces CPU load on your hosting, useful for busy or shared servers</li>
<li>Quotas and limits depend on your Lite, Pro or Unlimited plan</li>
<li>Works alongside local mode you can always fall back to local processing</li>
</ul>
You can choose your preferred processing mode in SEO Image Optimiser – Settings.
<h3>Free (Lite API Key)</h3>
The Lite API Key requires no card, only an email to issue an API key.
Included in the Lite API Key plan:
<ul>
<li>Unlimited local image conversions (WebP/AVIF) on your own server</li>
<li>Up to 50 cloud/API image conversions per month (WebP + AVIF) via the Web Wonderland Image API</li>
<li>Front-end WebP & AVIF delivery if available</li>
<li>Up to 30 AI alt tag & title generations per month</li>
<li>Automatic backups of originals with one-click restore</li>
<li>Works on one WordPress site</li>
</ul>
Your previously converted images remain on your server regardless of the API Key status. 
If your monthly cloud API quota is reached, the plugin can still optimise images locally.
<h3>Pro API Key</h3>
For busy sites and image-heavy blogs.
Includes everything in Lite plus:
<ul>
<li>Unlimited local image conversions (WebP/AVIF)</li>
<li>Effectively unlimited cloud/API image conversions for most sites 
(high cap WebP & AVIF generation via the Web Wonderland Image API)</li>
<li>Up to 3,000 AI alt tag & title generations per month</li>
<li>Background processing & bulk optimisation</li>
<li>Can be used on up to 5 WordPress sites</li>
</ul>
<h3>Unlimited API Key</h3>
For agencies or users managing many sites.
Includes everything in Pro plus:
<ul>
<li>Unlimited sites</li>
<li>Unlimited local image conversions (WebP/AVIF)</li>
<li>Unlimited cloud/API image conversions (WebP & AVIF for every image)</li>
<li>Up to 10,000 AI alt tag & title generations per month</li>
<li>Background processing & bulk optimisation</li>
</ul>
<h3>AI & Privacy</h3>
AI captioning is optional. If enabled, SmartAlt uses external services as documented in the External services section below. The plugin does not send personal data about site visitors.
<h3>External services</h3>
This plugin can connect to external services operated by Web Wonderland to provide optional “cloud” features (remote image optimisation and AI-powered SmartAlt captions). Local-only optimisation features continue to work without any external service.
When any cloud feature is enabled/used, the plugin sends requests from your WordPress server (admin-side actions) to the endpoints below. The plugin does not send personal data about site visitors.
<h4>1) Web Wonderland Image Optimisation API (Remote conversions)</h4>
Service: Web Wonderland Image Optimisation API 
Domain: imageapi.webwonderland.co.uk 
Used for: Cloud/remote image conversions (WebP/AVIF generation) and job completion signalling.
Endpoints used: 
– https://imageapi.webwonderland.co.uk/v1/jobs (create remote jobs) 
– https://imageapi.webwonderland.co.uk/v1/jobs/{job_id}/complete (mark job completed)
Data sent: 
– API key (sent as a request header) 
– attachment ID and public image URL (or secure URL) for the image being processed 
– derived image sizes and output settings (format, quality, width/height) 
– plugin version and basic site identifier (e.g. domain) where needed for returning results
When sent: 
– Only when you enable Cloud/API processing and run optimisation from the plugin dashboard / bulk optimiser. 
– The “/complete” request is sent after the plugin has successfully downloaded and stored the processed files.
Terms: https://www.webwonderland.co.uk/wwsio-terms/ 
Privacy: https://www.webwonderland.co.uk/wwsio-privacy-policy/
<h4>2) Web Wonderland Cloud Services (Netlify-hosted endpoints)</h4>
Service: Web Wonderland Cloud Services endpoints (Netlify) 
Domain: stupendous-pie-54cb74.netlify.app 
Used for: Site connect/disconnect, cloud api usage metering, background job coordination, and SmartAlt caption proxy.
Endpoints used: 
– https://stupendous-pie-54cb74.netlify.app/api/sio/connect 
– https://stupendous-pie-54cb74.netlify.app/api/sio/disconnect 
– https://stupendous-pie-54cb74.netlify.app/api/sio/check-reserve 
– https://stupendous-pie-54cb74.netlify.app/api/sio/cron-sites 
– https://stupendous-pie-54cb74.netlify.app/.netlify/functions/sio-smartalt-caption
Data sent: 
– API key (Authorization: Bearer or X-API-Key header, depending on endpoint) 
– plugin version 
– site identifier (e.g. domain) and/or anonymous instance ID 
– for SmartAlt caption generation: the image URL or a data URI for the selected image, and a small request payload (e.g. “usage” mode)
When sent: 
– Connect/disconnect: when you add or remove an API key in the Cloud Services screen. 
– Metering: when cloud processing runs or when SmartAlt is used. 
– Cron coordination: when the plugin is activated and when the optimisation queue state changes. 
– SmartAlt caption proxy: only when you click generate caption / suggestions in the SmartAlt admin screen.
Terms: https://www.webwonderland.co.uk/wwsio-terms/ 
Privacy: https://www.webwonderland.co.uk/wwsio-privacy-policy/
<h4>3) Replicate (AI provider used by Web Wonderland Cloud)</h4>
Service: Replicate (replicate.com) 
Used for: AI image captioning behind the SmartAlt feature (processed by Web Wonderland Cloud).
Data sent: 
– the image data or image URL required to generate a caption (sent by Web Wonderland Cloud, not directly by your WordPress site)
When sent: 
– only when you use SmartAlt caption generation in the plugin admin.
Terms: https://replicate.com/terms 
Privacy: https://replicate.com/privacy

Web Wonderland SEO Image Optimiser

Convert images to WebP and AVIF, add picture markup, and optionally generate SEO alt text & titles using AI. Fast, safe, and theme-friendly.

JZB Image Auto AVIF vs Web Wonderland SEO Image Optimiser