Faceted navigation is normally found in the sidebar of an ecommerce website and contains filters, allowing users to select and search combinations of the product attributes. As a result the web page shows a list of products bespoke to the users needs.
Facets act as indexed categories helping to specify a product listing while acting as an extension of the sites main categories. Best practice dictates that facets should add a unique value for every selection. As facets are indexed, every facet on a website should signal relevance to search engines by ensuring that all important attributes appear within the content of the page.
Although filters are used to sort or select items within a category page they don’t necessarily change the page content (it remains the same, just sorted in a different order), which usually leads to multiple URLs generating duplicate content issues. Thus, leaving all facets and filters crawlable and indexable can lead to:
- duplicate content issues
- wasting Google’s computational fixed resources allocated to crawling your website
- dilution of page level authority
- keyword cannibalisation
Best Practice
- Consult your analytics data to establish commercially valuable facets i.e. those that obtain traffic and conversions
- Block search engine access to non-commercially valuable facets in the robots.txt (using the
Disallow:directive), meta robots (“noindex, nofollow"), facet navigation links (rel = nofollow) - Canonicalise similar content (either by search intent, product variation or both) within faceted results to the ultimate parent node
- Prevent clickable links when no products exist for the category/filter
- Each page should link to its children and parent (easily achieved with breadcrumb trails) and sibling pages, where appropriate.
- Ensure attributes are always ordered in the same way, otherwise this may result in duplication issues.