How to fix seo variant urls not canonicalized on BigCommerce

Steps for BigCommerce

1. BigCommerce automatically outputs a canonical tag on product pages using the base product URL. Go to Storefront → My Themes → your active theme → Edit Theme Files.
2. Open templates/pages/product.html (or the equivalent Stencil template). Search for 'canonical'.
3. The canonical is typically output via a Handlebars helper such as {{canonicalUrl}} or set globally by the platform. Verify it resolves to the base product URL (without option/variant parameters).
4. If your theme or a custom script appends variant query parameters to the canonical, override it: set the canonical tag manually to {{urls.product}} which resolves to the base product URL.
5. Confirm in BigCommerce's built-in SEO settings: go to Store Setup → Store Settings → Search Engine Optimization and ensure 'Canonical URL' options favour the base product path.
6. Check your XML sitemap (Marketing → Sitemap) to confirm only base product URLs are listed, not variant URLs.

What is seo variant urls not canonicalized?

When shoppers (or your platform) navigate to a product with a colour, size, or style selected, the URL often changes — a query parameter like `?color=Pop+Red` or `?size=M` gets appended to the base product URL. Each of those variant URLs is effectively a separate page in Google's eyes. A canonical tag is a small snippet of HTML code (placed in the `<head>` of a page) that tells search engines: "The true, original version of this content lives at this URL." Pointing every variant URL's canonical at the clean, base product URL is the standard way to tell Google that all those variants are the same product, just filtered differently.

Without canonical tags on variant URLs, Google may index hundreds or thousands of near-duplicate pages for a single product. This splits your page's authority (link equity) across all those URLs instead of concentrating it on one, directly weakening your product page's ability to rank. Google may also choose a variant URL as the canonical itself — one that may disappear when stock runs out — causing rankings to drop unpredictably. Crawl budget is wasted re-crawling redundant variants instead of discovering new or updated pages. Fixing this consolidates all ranking signals on your main product page, typically improving organic visibility and protecting you against ranking volatility as variants come and go.

See the complete Seo variant urls not canonicalized guide for every platform and the full background.