WordPress image optimization: the 10-minute setup

Open any slow WordPress site and the first thing you will find is 2 MB hero images. WordPress does generate thumbnails, but the original is still served to visitors who view the full-size image, and thumbnails themselves are often needlessly heavy.

Step one: compress on upload. Our plugin (or any good compressor) hooks wp_generate_attachment_metadata so every image and thumbnail is optimized the moment it lands in the Media Library. Do this and new content is automatically fast.

Step two: compress your existing library. Bulk-compress in batches — 5,000 images takes a while, so run it overnight and let it report per-file results.

Step three (optional): serve WebP/AVIF via a CDN or <picture> tags. Only do this after compression — compressing first is 90% of the win, format conversion is the last 10%.

The whole setup takes about ten minutes and typically cuts page weight by 60–80%. Your Core Web Vitals will send you a thank-you note.