
Assignment of image sizes to post types
Every time you upload an image, WordPress doesn’t just store your file — it generates a separate cropped copy for every registered image size. A fresh install already creates three (thumbnail, medium, and large) on top of the original, so a single upload becomes four files on your server.
Themes and plugins add many more. A typical site might register hero, slider, product thumbnail, team member, and testimonial sizes — and WooCommerce adds several of its own. With six registered sizes, one upload turns into seven files, even when the page only ever displays one of them. The rest sit on disk doing nothing but consuming space.
Multiply that across hundreds of posts, pages, and products and the waste adds up fast: bloated storage, slower backups, and longer upload processing. It’s especially painful on WooCommerce sites, where uploading a single banner or hero image also generates the full set of product thumbnail sizes you’ll never use for that image.
WP Image Sizes fixes this by letting you decide which sizes WordPress is allowed to create.
The result is a leaner media library, less wasted disk space, and a faster, lighter WordPress site.
The free plugin controls which sizes get generated on new uploads. WP Image Sizes Pro extends this to your existing media and adds automation: