How does Layered Navigation work?
When a customer is browsing through your site they need to find the products that interest them as fast as possible or you won’t make the sale. And when confronted with a category containing 60 products spread across multiple pages most customers will simply throw in the towel. Give them the option to filter by what interests them though, whether it’s price, manufacturer or any other aspect of the products, and you can show your customers what they want and raise conversions.
Layered navigation constant filters
In Magento, two properties will appear as layered navigation filters without you having to do anything: Price and Categories. If you make a category an anchor category, its sub-categories will display as layered navigation options. If you take a look at the image above, you’ll notice the first filter is Category and it features two options: Shirts and Pants. In this example, Shirts and Pants are subcategories of the category this layered navigation block was pulled from.
Price ranges are also logically picked to display as another filter. The ranges themselves are determined by the prices of products contained within. There will never be more than 10 price ranges displayed, and products will be distributed accordingly.
Additional layered navigation filters
The additional filters in the screenshots above are Color and Manufacturer. These are product attributes that have been selected as filterable in the Use in Layered Navigation dropdown. There are two types of filterable attributes. Filterable (with results) means that links will only appear for values where the number of results (the number in parentheses next to each value) is greater than zero. Filterable (no results) means that links will appear for all values, whether the number of results is zero or greater. In order for an attribute to appear as a layered navigation filter, the Catalog Input Type for Store Owner must be Dropdown, Multiple Select, or Price. This controls the number of possible filter options, and makes them consistent.