Filters and facets in ecommerce: what to index and what to block.
Filters improve the shopping experience, but they can generate thousands of near-identical URLs. Google’s guidance is clear: if you don’t need them indexed, stop them from being crawled; if you need them, take care over how they are built.
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Why filters cause problems.
Each combination of size, colour, price or sort order can create a different URL. The result is duplicate pages, crawling wasted on low-value URLs and signals spread across too many variants.
Google has pointed out that faceted navigation is one of the most common sources of excessive-crawling problems among the sites that consult it.
First decide which combinations deserve indexing.
- There is real search demand (for example, a combination of product type and colour that people search for).
- It has enough products to be useful.
- It can have its own title, H1 and a short text.
- It is stable: it doesn’t disappear every time a product sells out.
Combinations that don’t meet that shouldn’t be indexed or waste crawl budget.
How to stop the ones that aren’t worth it from being crawled.
robots.txt
Block parameter patterns so Google doesn’t crawl them. It saves crawl budget, but Google won’t be able to read tags inside those pages.
Filters without crawlable links
Build the filters so they don’t create links that Google follows, or use # fragments that don’t count as different URLs.
noindex
The page is crawled but not indexed. Use it when you need Google to see it. It doesn’t save crawl budget and you shouldn’t combine it with a robots.txt block on the same URL.
Canonical
It is a signal, not an order. It works for variants, not for controlling crawling.
Good practice when building URLs.
- Use the standard parameter format (key=value separated by &) and a consistent order.
- If a combination has no products, return a 404 instead of an empty page.
- Link internally only to the combinations you want indexed.
- Include only those combinations in the sitemap.
How to check your case.
- Crawl your store with a crawler and count how many URLs with parameters appear.
- In Search Console, check which URLs with parameters are indexed.
- In the crawl stats, look at which URLs Googlebot visits most.
- Compare with your sitemap: if Google crawls far more than you declare, there is a leak.
Each platform behaves differently.
Collection filters on Shopify, WooCommerce filtering plugins and PrestaShop facet modules generate URLs in different ways. We go into detail on our pages for Shopify SEO agency, WooCommerce SEO agency and PrestaShop SEO agency.
Frequently asked questions
Should I index all filters?
No. Index only the combinations with search demand, enough products and their own content.
Is a canonical enough?
Not always. Google treats it as a hint and it doesn’t stop Google from crawling those URLs.
Does this matter for AI?
There are no guarantees, but a site with clear URLs and no duplicates is easier to understand for search engines and for the systems that read your website.
Does your store generate thousands of filter URLs?
In the technical audit we measure how many URLs Google crawls and how many it indexes, and tell you which are surplus.
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