Listed below are a few common reasons for why reviewing some of the more common reasons products don’t display in Magento.
1. Product updates have invalidated the cache
When using the Magento cache option, a refresh is required after product updates.
System > Cache Management
The invalidated cache will be displayed in orange.
2. Product is not assigned to a website and will not display in Magento
Catalog > Manage Products > Website (tab)
3. Product is not assigned to a category
Catalog > Manage Products > Category (tab)
4. Product is out of stock
Catalog > Manage Products > Inventory (tab)
By default, products with a ‘Stock Availability’ of ‘Out of Stock’ (OOS) are not displayed on category pages. Though, they can be accessed directly via the products URL.
You can change the default setting to display OOS products System > Configuration > Catalog > Display Out of Stock Products (change value to Yes).