No control over your robots.txt file
The problem. Shopify does not allow store owners to edit their robots.txt file. This is an issue because the platform creates duplicate URLs for products associated with a collection/category page.
“The ideal solution would be to use robots.txt disallow directives to block these pages from being crawled in the first place,” Kevin Wallner, founder of First Chair Digital, told Search Engine Land, noting that, while Shopify does add canonical tags pointing back to the correct product URL, this does not prevent the duplicate URLs from being crawled and potentially indexed.
Solutions: Editing your Shopify theme, as discussed in our technical SEO for Shopify guide, is one way to resolve this issue. Alternatively, pages not included in your robots.txt file can be hidden from search engines by customizing the section of your theme’s layout file, as detailed on this Shopify help page.
You can also use an app such as Sitemap & NoIndex Manager to add noindex tags and remove URLs from your sitemap, Wallner suggested. “Unfortunately this won’t work for duplicate product URLs, but it works for several other special Shopify page types with little to no SEO value, so it’s still a good move,” he said.
Related: Shopify SEO Guide: How to increase organic traffic to your store
Wallner also advised that store owners avoid linking to duplicate URLs in their header, footer, sidebars, breadcrumbs and within the text on their pages. If particular pages have earned important backlinks, store owners can also get in touch with webmasters to request that they link to the preferred URL.