WebberZone Image Optimizer – WebP & AVIF Converter, Compress Images

1. 01Upload the webberzone-image-optimizer folder to /wp-content/plugins/ .
2. 02Activate the plugin through the Plugins menu.
3. 03Visit Media → Image Optimizer to choose your formats.
4. 04Visit Media → Bulk Optimize and press Start.

Will this touch my original images?

By default, originals are unchanged and modern copies are separate files. Enable Compress original images to recompress served JPEG/PNG files with mandatory backups. Restore originals reverses compression and optional resizing. The unscaled upload retained by WordPress is left untouched.

What happens if I deactivate the plugin?

Your site immediately goes back to serving the original images. The generated files stay on disk, so reactivating restores the optimization instantly without converting anything again.

Do I need to change my server configuration?

No. The <picture> rewrite needs nothing beyond activating the plugin. Server rules are only needed for images referenced from CSS, and they are optional.

Do I need an API key or an account?

No. Conversion and JPEG compression run on your own server with Imagick or GD, the image libraries WordPress already uses; PNG compression also needs oxipng or pngquant on the server. There is no sign-up, no monthly quota and no limit on how many images you convert, and it works the same on staging and local sites.

Is AVIF conversion free?

Yes. There is no paid version; WebP, AVIF, bulk conversion, compression and WP-CLI are all included. AVIF only needs a server that can encode it, and the settings screen tells you whether yours can.

Will this improve my PageSpeed Insights score?

Smaller images mean fewer bytes to download, which is what PageSpeed Insights measures in its image delivery audit and what most often slows Largest Contentful Paint. The plugin does not lazy load images or change their dimensions, so keep whatever handles those today.

I am switching from another image optimizer. Do I have to convert everything again?

No. WebP and AVIF files left next to your originals by plugins such as ShortPixel, Imagify or EWWW Image Optimizer are served as they are. The plugin detects which naming those files use and offers to match it, and the bulk run only creates the formats that are missing. Do not use the old plugin’s restore tool before switching, as that deletes its optimized copies. See Migrating from another image optimizer .

Should I enable AVIF?

AVIF produces noticeably smaller files than WebP and is understood by every current browser, but it takes longer to encode and a small number of older browsers do not support it. Generating both is the safest choice: each visitor gets the smallest file their browser can read, and anyone else gets the original. Start with WebP if your library is very large.

My server cannot encode WebP or AVIF

The settings screen marks any format your server cannot produce. Ask your host to enable the Imagick extension, which is the better backend, or GD compiled with WebP support.

One of my images is still being served as a JPEG or PNG

There are three common reasons, and the Media library column tells you which one applies.

The image is not hosted on your site. Only files inside your own uploads directory can be optimized. Posts imported from another site often keep image URLs pointing back at the original domain, and those are left alone.

One size in the set could not be made smaller. A lossy optimized copy that misses the minimum saving is retried once at a lower quality and discarded if it still misses. Lossless copies are simply discarded when they miss. Missing intermediate copies are left out of the optimized srcset , so the browser can still use the copies that exist. If the smallest, widest or highest-density copy is missing, that optimized format is withheld to avoid over-downloading or serving an undersized image where the original set offered a better choice.

Your server cannot produce that format. Check the settings screen, which marks any format your server cannot encode.

Does this work with a CDN or a caching plugin?

Yes. Because the format choice happens in the browser rather than on the server, every visitor receives identical HTML and the page cache stays correct. If you also add the optional server rules for CSS backgrounds, keep the Vary: Accept header they include.