How to fix seo facet url not canonicalized on Shopify

Steps for Shopify

1. Shopify automatically outputs a self-referencing canonical on most pages, but it does NOT automatically set a canonical on facet/filter URLs generated by third-party filter apps or ?sort_by= and ?page= parameters.
2. Open your theme code: Online Store → Themes → Actions → Edit Code.
3. Open the file 'layout/theme.liquid'. Locate the existing <link rel="canonical"> tag (search for 'canonical').
4. Replace or wrap the canonical logic so that for collection pages, the canonical always outputs the clean collection URL without query parameters. Use Liquid: {% assign canonical_url = canonical_url | split: '?' | first %} then <link rel="canonical" href="{{ canonical_url }}">.
5. If you use a faceted-search app (e.g. Boost Commerce, Searchpie, Filterify), check the app's settings for a 'Canonical URL' or 'SEO' section — many have a built-in toggle to enforce canonicals. Enable it.
6. Save changes and use the URL Inspection tool in Google Search Console to verify the canonical on a filtered URL (e.g. ?sort_by=price-ascending) now points to the clean collection URL.

What is seo facet url not canonicalized?

When shoppers filter your product listings by size, colour, price, or sort order — or browse to page 2, 3, etc. — your store generates a new URL for each combination (e.g. `/collections/hoops?color=red&sort=price` or `/collections/hoops?page=5`). These "facet URLs" display largely the same products as the base category page, making them near-duplicate pages. A canonical tag is a small piece of HTML that tells Google: "Treat THIS page as the authoritative, indexable version — not the one you just crawled." Pointing every facet URL's canonical back to the clean category URL (e.g. `/collections/hoops`) is the standard, Google-recommended way to handle this.

Without canonical tags, Google may index hundreds or thousands of near-identical filter and pagination URLs instead of your core category pages — diluting the ranking signals (links, authority, clicks) that should be concentrated on those pages. Crawl budget is wasted on low-value filter combinations, meaning new or updated products get discovered more slowly. Duplicate content confusion can push the wrong URL into search results, giving shoppers a paginated or pre-filtered page that looks broken. Fixing canonicals consolidates ranking signals onto your clean category pages, improves crawl efficiency, and protects your organic traffic from unnecessary duplication penalties.

See the complete Seo facet url not canonicalized guide for every platform and the full background.