Pixellize Image Optimizer
Auto-convert every image you upload to WebP, bulk optimize your existing library, and serve WebP everywhere, including page builders and CSS backgrounds. No paid tier, no setup wizard, just install and forget.
Twelve things you get out of the box
Every image you add to your Media Library is converted to WebP, in every thumbnail size, and wired into your existing posts, pages, and responsive markup. Your existing library gets the same treatment with one click.
Automatic on Upload
JPG, JPEG, PNG, BMP, and AVIF files are converted the moment they hit your Media Library. No bulk operations to run, no buttons to click.
Bulk Optimize Your Library
New in v0.5: one click builds WebP for every image already in your library, with a live progress bar. The run continues in the background even if you close the tab, and originals are always kept.
Serve WebP Everywhere
New in v0.5: a server-level toggle that delivers WebP for images from themes, page builders, custom fields, and CSS backgrounds. If an image has no WebP, its real format is served, so nothing breaks.
Resize Large Uploads
New in v0.5: optionally scale huge uploads down to a maximum width or height (default 2048px) before conversion. This often saves more than the conversion itself. Off by default.
Optimize Any Page in One Click
New in v0.5: an Optimize images button in the admin toolbar builds WebP for just the page you are viewing, with a live count, then clears the cache and reloads so you see the result immediately.
Every Thumbnail Size
WebP is generated for the full image and every thumbnail size your theme registers, so responsive srcset markup is fully covered.
Keep Original Mode
An optional toggle that keeps your source files in the Media Library alongside the WebP. Useful when you offer downloads of originals or need to re-edit later.
One-Click Restore
A Restore link in the Media Library row actions for any WebP attachment that has its original on disk. Rolls a single image back without touching anything else.
URL Replacement Site-Wide
Old image URLs are swapped for the new WebP version inside post content, image tags, and the responsive srcset attribute, so visitors instantly see the lighter file.
Adjustable Quality
Pick a WebP quality between 0 and 100. The default of 85 hits the sweet spot between visual quality and file size for most sites.
Savings Panel
The settings page shows total images converted, original size, WebP size, and total bytes (and percentage) saved. Reset the counter any time.
Safe Fallbacks
Uses the GD library by default, falls back to Imagick if GD is missing, and refuses to activate at all if neither library is available, so you never end up in a broken state.
Faster pages with no design compromise
WebP files are typically twenty to forty percent smaller than the equivalent JPG or PNG, with the same visual quality. Smaller files mean better scores where they actually count.
Better Core Web Vitals
Smaller hero and gallery images load sooner, lifting your Largest Contentful Paint score and reducing layout jumps caused by slow image loads.
Stronger SEO Signals
Page speed is a confirmed Google ranking factor. Lighter images move you up the rankings without rewriting a single article.
Lower Bandwidth Bills
If you pay for hosting bandwidth or CDN traffic, smaller image files translate directly into a smaller monthly bill. The savings compound on busy sites.
A plugin you can forget about
The best image optimizer is the one you stop thinking about after install. Pixellize Image Optimizer was built for that. There is no daily check-in, no quota meter, no console to monitor. You upload your images the way you have always uploaded them, and the WebP version is in place before the upload screen even closes.
Behind the scenes, every URL on your site is rewritten to point at the new WebP file: image tags in post content, attachment metadata, and the responsive srcset attribute that browsers use to pick the right size. WebP copies are generated for the full image AND every thumbnail size your theme registers, so responsive markup is fully covered. And with v0.5, the server-level delivery option covers everything else too: page builder images, custom fields, and CSS backgrounds.
If a conversion ever fails because of an unusual file, the original is left untouched and a clear admin notice tells you what happened. Nothing silently disappears. The result: a quieter Media Library, lighter pages, and one less plugin you need to babysit.
Three steps and you are done
No signup, no API key, no third-party service. Everything happens inside your WordPress install.
Install & activate
Search “Pixellize Image Optimizer” in your Plugins menu, click Install, then Activate. The plugin checks for GD or Imagick before it activates.
Set the quality (optional)
Go to Tools then Pixellize Image Optimizer to adjust WebP quality. The default of 85 works for most sites. Turn on Keep Original to keep source files, and run Bulk optimize to convert the images already in your library.
Upload as usual
Drop images into your Media Library the way you always do. WebP versions are generated automatically and used everywhere on the site.
Roadmap for upcoming releases
The plugin is actively developed. Here is what is on deck for the next major release.
Lazy Loading Integration
Smarter lazy loading that plays well with the WebP swap, so below-the-fold images cost nothing until the visitor scrolls to them.
CDN-Aware Rewriting
Tighter compatibility with popular CDNs (Cloudflare, BunnyCDN, KeyCDN) so off-loaded images stay in WebP form and the original-URL fallback never breaks.
AVIF Output
Optional AVIF output alongside WebP, for browsers that support it. AVIF is typically another 10-20 percent smaller than WebP at the same quality.
Quick answers before you install
Which image formats are supported?
JPG, JPEG, PNG, BMP, and AVIF. GIF is not supported because animated images would lose their frames during conversion.
Will it convert images I already uploaded?
Yes. New in v0.5: go to Tools then Pixellize Image Optimizer and click Start bulk optimization. It builds a WebP version for every image already in your library, including all thumbnail sizes, with a live progress bar. Originals are kept, so nothing breaks.
Does the bulk run stop if I close the tab?
No. The run continues in the background through a scheduled task and finishes on its own. Come back to the settings page any time and the progress bar resumes where it left off.
Does it cover page builder and theme images?
Yes. New in v0.5: turn on Serve WebP everywhere in the settings (with Keep Original on) and the server delivers WebP for any image that has one, including page builders, custom fields, widgets, and CSS background images.
Is the original image deleted?
By default yes, the upload is replaced by a WebP after a successful conversion to save disk space. Turn on Keep Original in the settings to keep the source file in your Media Library and enable one-click restore later.
Can I get an image back to its original?
Yes, when Keep Original is on. A Restore link appears in the Media Library row actions for any WebP attachment that has its original on disk. Clicking it points the attachment back at the original file, rebuilds all sizes, and removes the WebP copies.
What if my server does not support GD?
The plugin automatically falls back to Imagick. If neither library is available the plugin refuses to activate and shows a clear admin notice, so you cannot end up in a broken state.
Can I control image quality?
Yes. Quality is adjustable from 0 to 100 with a default of 85. Lower values mean smaller files and slightly lower visual quality.
What happens if I upload a file that is already WebP?
It is skipped entirely. No re-encoding, no duplicate file, and no extra work for your server.
How much space am I saving?
The settings page shows a savings panel with the total number of images converted, the original size, the WebP size, and the total bytes (and percentage) saved. Reset the counter any time.
Where can I read the full documentation?
The full documentation, including installation, every setting, every supported format, and the changelog, lives at pixellize.io/docs/pixellize-image-optimizer.
How do I get help or report a bug?
Use the support tab on the WordPress.org plugin page, or email [email protected]. We read every message and reply within one to two business days.
Lighter images in the next minute
Install v0.5 from WordPress.org, bulk optimize your existing library, and serve WebP versions of every image, in every thumbnail size, automatically.