Thumbnail images (or "thumbs") allow a page to load faster and also help identify products quicker, offering the advantage of simultaneously presenting a large number of images on the page.

To speed up the page load time, these images are resized and compressed according to the page’s CMS configuration. If the image file size (in KB) is too small, distortions may compromise the thumbnail quality, therefore we recommend increasing the image size until the quality is satisfactory.

To perform this configuration:

1. Go to Store setup > CMS > Settings.
2. Go to the File type tab.
3. Click Edit on the Produto - Thumb row.
4. In the display, you can choose the maximum file size for the thumbnails in the Maximum size in Kb field.

To learn how to improve the quality of any image from your store without compromising the page load performance, we also recommend reading the article Improving the performance of product images.