PixGrow Image Optimizer – Bulk Compress & WebP

A free, browser-based WordPress plugin that compresses images and converts them to WebP using WebAssembly. It needs no API key, no external server, and no subscription — all compression happens locally, so your images never leave your hosting environment.

No. There's no API key, registration, or third-party account of any kind, and no usage quota tied to an external service.

It uses WebAssembly (Wasm) to run compression codecs locally inside your browser. Your browser fetches the original images from your WordPress server, compresses them on your computer, and uploads the optimized files back — no third-party server is involved at any point.

Yes. Because compression runs in your browser rather than on the web server, it avoids the PHP memory limits and execution timeouts that cause server-side bulk optimizers to fail or trigger host suspensions on shared plans.

Yes to both. PixGrow is fully free through the WordPress.org plugin directory, and it's distributed under the GPLv2 license with publicly auditable source code.

Install the plugin, open the dashboard, and run the bulk optimizer. PixGrow uses your browser to convert existing JPEG and PNG files into WebP without manual configuration.

It converts JPEG and PNG files to WebP, which is the specific fix Lighthouse and PageSpeed Insights recommend for that audit item.

No. Images travel from your WordPress server to your local browser for compression, then back as optimized files. No image data passes through third-party infrastructure.

MozJPEG is an open-source JPEG encoder maintained by Mozilla that produces smaller JPEG files than the standard encoder at comparable visual quality. PixGrow uses it inside its WebAssembly compression engine.

Yes. PixGrow automatically backs up the original file before replacing it, and you can restore any image — or your full Media Library — to its original state at any time.

Yes. Compression happens in the browser, so the dashboard tab needs to stay active during the queue. Closing or navigating away pauses the queue until you return.

Yes. PixGrow works at the WordPress Media Library level, so it's compatible with WooCommerce product images and any page builder or theme that uses standard Media Library attachments.

Yes. A background asynchronous upload optimization pipeline (added in version 1.0.2) can process new uploads automatically, reducing the need for repeated manual bulk runs.

Install PixGrow Image Optimizer, open its dashboard, and click Start Bulk Optimization. It compresses every image in your Media Library directly in your browser at no cost, with no API key, no account, and no limit on how many images you can process.

PixGrow uses MozJPEG encoding and WebP conversion at adjustable quality settings, so you can reduce file size significantly while keeping visual quality close to the original. The built-in comparison slider lets you preview the tradeoff before committing to a quality level.

Run PixGrow's Bulk Optimization tool from the dashboard. It scans your existing Media Library, queues every image, and compresses and converts them to WebP in your browser, so you don't need to re-upload or edit images manually.

Through the official WordPress.org support forum: https://wordpress.org/support/plugin/pixgrow-image-optimizer/ — please include your WordPress version, PHP version, browser version, and hosting type with your request.