This translation has not been editorially reviewed yet. The German version is authoritative. Deutsche Fassung
SEO
Variant and filter addresses: a canonical to the main address
A shop easily generates dozens of addresses for a product:?color=red,?size=m,?sort=price,?page=2. For Google, each of them is a separate page with almost the same content. Without specifying which is the main address, the effect is distributed among all variants and none is good. The SEO test area checks on shop pages with such parameters whether a canonical without these parameters is set.
What exactly is checked
If the measured address carries parameters that denote a variant or a filter (color, color, size, size, variant, sku, filter, sort, order, page, price, brand and related), the measuring core reads the canonical of the page. If he is missing or he himself carries one of these parameters, the result is the finding with the found parameters. Tracking parameters such as utm source do not count as a variant.
Why it matters
Google itself chooses a main address without a canonical, and this is often the wrong one: a filter view without text or a variant that hardly anyone is looking for. Internal links, external references and the evaluation of the page are spread over many addresses. A canonical bundles this to the product page or category.
Limitations of the test
The checking area only measures addresses that the crawl reaches. A filter address that is not linked anywhere is not measured. Whether a variant deserves its own page (for example, a color that is specifically sought) is a decision of the shop; then she gets her own content and her own canonical.
- On product pages with variants, set a canonical to the address without parameters; Most shop systems have a setting in the SEO module.
- Canonize filter and sort views of categories to the category page and additionally mark them via robots meta noindex if they do not serve their own search intent.
- Pages (page=2) canonize on themselves and connect to rel=prev/next or an overview page; Do not show everyone on page 1.
- After the changeover, check a variant address in the source text: the canonical points to the main address, the parameters are missing.
