1. Facets, filters and categories
A category places a product in one area of the catalogue, for example garden furniture. A facet describes a property of the products in the current result list, for example material: aluminium. Shoppers can combine several facets without you creating a category for every possible combination.
The terms facet and filter are often used for the same thing. A useful distinction: a filter is any rule that removes products from a list, while a facet is a filter that is built from the results themselves and usually shows how many products each value has. If a facet lists colours with counts, such as black (12) and white (4), values without matching products can be hidden, so a click does not lead to an empty page.
Example: finding a patio chair
A search for "garden chair" returns 140 products. Material "aluminium", colour "anthracite" and a price range of 50 to 150 turn it into a short list. All three properties must be maintained on each product; no search can reliably guess missing manufacturer data.
2. Typical facets in online stores
Which facets make sense depends on how your customers decide. A shoe shop needs size and width, a tool shop voltage and battery system, a wine shop grape, region and vintage. Price, brand and availability work in almost every catalogue.
- Value lists: colour, material, brand, size. Shoppers can usually tick several values of one facet, for example black or grey.
- Number ranges: price, length, power, capacity, shown as a slider or two input fields.
- Yes or no: in stock, on sale, suitable for outdoor use.
- Category as a facet: useful in search results, where one query can hit products from several categories.
3. Consistent data makes facets understandable
Decide which attributes are value lists and which are number ranges. Measurements need one unit: 50 cm and 0.5 m must not appear as two different numbers. Product codes with leading zeros stay text and do not belong in a slider. Spelling matters too: "Grey", "gray" and "grey " with a trailing space become three separate values in a facet.
Products with several values need them as separate values. A chair suitable for indoor and outdoor use should carry both values, not one text "indoor, outdoor". Start with three to five attributes that customers really use to decide. A long list of half maintained attributes makes the interface harder to use, especially on a phone.
4. Faceted navigation and SEO: what Google recommends
If your store writes every filter selection into URL parameters, such as ?color=green&size=small, a few facets produce a huge number of possible addresses. Google's crawling documentation calls faceted navigation a popular and useful feature, but warns that its most common implementation, based on URL parameters, can generate infinite URL spaces. The result is overcrawling and slower discovery of new, useful pages.
Google recommends one of two ways. If filtered pages do not need to appear in search, prevent crawling of these URLs, for example with robots.txt rules for the filter parameters, or use URL fragments (#) for filters, which Google Search generally does not support in crawling and indexing. Google suggests allowing crawling of the individual product pages and of a listing page without filters. If some filtered pages should rank, Google lists best practices: use & as the parameter separator, keep the order of filters in the URL path always the same, and return HTTP 404 for filter combinations without results.
Google also mentions rel="canonical" pointing to the unfiltered version and rel="nofollow" on filter links, but describes both as generally less effective in the long term than robots.txt or URL fragments.
- Search your server logs or Search Console crawl stats for parameter URLs with filter names.
- Decide which filter pages, if any, deserve to rank, for example a brand within a category.
- Block crawling of all other filter parameters in robots.txt and test the rules.
- Return 404 for filter combinations without products instead of an empty list with status 200.
5. Facets in Grumeria
Grumeria builds facets from the fields of your product feed. After the import you choose which fields appear as filters and give them a label that shoppers understand, for example Colour instead of attr_colour. Value lists and number ranges such as price are both supported.
The search widget shows results and facets in an overlay on your store page without creating new URLs for crawlers. If you switch on linkable searches, the query and the selected filters are written into the URL fragment after #, the method Google names as having no impact on crawling. You can check which products and fields your feed provides for free before installing anything.
Frequently asked questions
What is faceted search?
Faceted search lets shoppers narrow a result list by several properties at once, such as price, colour, material and brand. Each property is a facet, and its values usually show how many products match.
What is the difference between facets and filters?
The terms are often used interchangeably. A facet is a filter built from the current results, usually with a count per value, so only values that still match products are offered.
Is faceted navigation bad for SEO?
Not in itself. Google calls it a popular and useful feature, but warns that URL parameter implementations can create infinite URL spaces. Google recommends blocking filter URLs with robots.txt or using URL fragments if they do not need to rank.
Should filter pages be indexed?
Only those that match real search demand, for example a brand within a category. Google recommends allowing crawling of product pages and an unfiltered listing page and preventing crawling of other filter URLs.