Free WordPress plugin
Create WebP copies of your Media Library images without replacing the originals. Scan first, select the images to convert, and review the results. Serving WebP on the website is a separate setting, off by default.
What you can do
Check server support, preview the eligible images, and see why any file is skipped.
Readiness
Before you convert, the plugin checks WordPress image editors, GD or Imagick WebP support, PHP limits, and whether it can write to your uploads folder.
You control batch size, image dimensions, JPEG and PNG quality, and whether to skip a WebP file that would be larger than the original.
Conversion
A dry scan lists eligible JPEG and PNG images without converting them. Select the images you want; the plugin processes originals and available WordPress-generated sizes in small batches.
Each WebP is checked before it is saved. Originals stay in place. If a WebP from another tool already exists at the destination, the plugin reports a conflict and leaves it alone.
Delivery
Serving WebP and automatically converting new uploads are separate options, both off by default. WebP serving changes normal WordPress image output only when a matching generated file exists. Saved content and attachment URLs remain unchanged.
You can check generated WebP files, export the report, or delete the files created by the plugin. Cleanup leaves originals and unrelated files in place.
Inside version 0.1.5
Screenshots from the version 0.1.5 WordPress test environment. Select an image to enlarge it.
Scan, convert, validate
Check server support and scan your images before converting. Afterwards, validate or remove the WebP files created by the plugin.
Confirm that at least one local WordPress image editor can write WebP and that uploads are writable. Set a small batch, pixel ceiling, output quality, and whether larger WebP output should be skipped.
The dry scan lists eligible, skipped, and already converted images, plus any failures or conflicts. Each row includes image details and the reason for its result.
Only selected images are converted. You can pause, resume, or stop between batches; generated files are checked before being saved.
Review file sizes, savings, and any errors, then run Validate WebP. Download the report if you need a record before enabling WebP serving or automatic conversion of new uploads.
Conversion results
The report shows original and WebP sizes, savings, status, and the reason for a skip or failure. Download it as CSV when needed.
Before conversion
See which Media Library attachments and generated sizes are available before selecting anything for conversion.
After conversion
The same report adds generated WebP size, observed savings, writer, status, and the number of full-size and generated files produced.
Outside wp-admin
Download the current results to share or keep before cleanup. Values that could be interpreted as spreadsheet formulas are escaped.
Your data
Scanning, conversion, validation, serving decisions, export, and cleanup run inside WordPress. The plugin does not create an IndexLane account, upload media to an external optimizer, call a cloud conversion service, or add telemetry.
Requires WordPress 6.0+ and PHP 7.4+ and is tested through WordPress 7.1 with GD and Imagick coverage. Conversion safety depends on the image editors and resources available on the site's server. Original JPEG and PNG files remain. Frontend WebP serving and automatic conversion for new uploads are separate options and are off by default.
Free and open source
Install version 0.1.5 from the official WordPress Plugin Directory, then open Tools → IndexLane Safe WebP Queue in wp-admin and run the dry scan.
Help with your website
Converting images is one part of performance work. I can help check image delivery and find other causes of slow pages.
Install from WordPress.org