This tutorial will show you how to regenerate thumbnails in PrestaShop 1.6.x.
Log into your PrestaShop admin panel and open Preferences -> Images:
Scroll down untill you see Regenerate thumbnails button. Thumbnails regeneration is something you need to do every time you upload images and change image sizes:
There you can select a type of images that should be regenerated – product images, categories images, etc.:
Click Regenerate thumbnails button and all the thumbnails will be re-built for you.
Feel free to check the detailed video tutorial below: