• Log in to the admin panel for your store.
  • Click Inventory then​ click on Manage Categories.
  • Click on the category for which you want to add a banner.
  • Next click on the Description Button.
  • Then look for the WYSIWYG editor labeled Description.
  • Insert your image inside the WYSIWYG editor.
 
 
  • Then click Save.
  • Note: Make sure the image you are using fits the size of the banner. ( Please note if you are using a responsive template to set the height to (height auto;) in the source code.