Does ShortPixel Image Optimizer add a lazy loading effect to the compressed images?

The ShortPixel Image Optimization plugin for WordPress does not add a lazy loading effect to the images. If you notice a lazy loading effect, this can be caused by:

• Your theme or another plugin is adding a lazy load effect.
• What you are seeing is not lazy loading, but progressive images.

Progressive images are images that load gradually. When the connection is slow, the gradual loading becomes visible.

Why are the images progressive?

Because when we optimize an image we choose between the progressive and the normal (baseline) version, depending on how small the final image will be. If the progressive version takes less space on disk, then we optimize and save the image as progressive.

As a general rule, very small images will be normal, while larger images will always be progressive after optimization, as they are smaller this way.