How does ShortPixel Image Optimizer work?

Our lightweight plugin sends your images to our Image Optimization Cloud, where they are compressed and optimized before being returned to your website. Here’s a step-by-step overview of how ShortPixel Image Optimizer (SPIO) works:

1. An image is uploaded to the site, or alternatively, you tell ShortPixel to optimize an existing image.
2. SPIO detects the image (and its thumbnails) and sends them to ShortPixel’s optimization servers.
3. The image and its thumbnails are optimized and sent back to the site, along with the generated WebP/AVIF files (if you chose to create them).
4. SPIO replaces the original unoptimized image (and its thumbnails) with the optimized versions from the optimization servers. Optionally, a backup is created.
5. If relevant, the WebP/AVIF files are stored next to the optimized images in the same directory.

This process is carried out for every image (and its respective thumbnails, if selected) you optimize on your site—whether through Media > Bulk ShortPixel, your Media Library (one by one), or for new uploads.

To clarify, ShortPixel Image Optimizer only replaces your physical image files:

• SPIO does not alter how your webpage looks.
• SPIO does not modify alt texts, titles, descriptions, or any other image metadata.
• SPIO does not change your webpage’s code—unless you choose not only to create WebP or AVIF files but also to deliver them using one of the following two methods: