How to fix non self canonical on Shopify

Steps for Shopify

1. Shopify auto-generates self-canonical tags for standard product, collection, blog, and page templates — so a non-self-canonical usually means a theme customization or app override is present.
2. In your Shopify admin go to Online Store → Themes → click 'Edit code' on your active theme.
3. Open the layout file (typically 'theme.liquid') and search for 'canonical'. If you see a hardcoded or overridden canonical tag (not the Liquid variable {{ canonical_url }}), replace it with the standard tag: <link rel="canonical" href="{{ canonical_url }}">.
4. Check any installed SEO apps (e.g., SEO Manager, Plug In SEO, Smart SEO) — open the app and look for a canonical override setting for the affected page type; disable or correct it.
5. For individual pages/products, some SEO apps let you set a custom canonical per-URL — find that setting and either remove the override or correct the destination URL.
6. Save changes, then use the Shopify storefront preview to view-source the affected page and confirm the canonical tag now matches the page URL.

What is non self canonical?

A canonical tag is a small snippet of HTML code, placed in the `<head>` of a page, that tells Google "this is the definitive version of this content." A self-canonical means the tag points back to the page itself — the norm for any page you want indexed. A non-self-canonical means the tag points to a different URL, effectively telling Google: "don't index me, index that other page instead." This is sometimes intentional (e.g., a filtered product-listing page deferring to the main category page), but when it happens by accident, Google will ignore the page entirely and index the wrong destination instead.

When a page has a non-self-canonical by mistake, Google treats it as a duplicate and removes it from search results — meaning all the organic traffic that page could earn is lost. If important product, category, or landing pages are accidentally canonicalized to the wrong URL, your store effectively disappears from Google for those queries. Even if Google doesn't fully honour the tag, it still dilutes your crawl budget and creates confusing ranking signals. Fixing accidental non-self-canonicals can restore lost rankings quickly, while verifying intentional ones ensures you're not accidentally de-indexing pages you need.

See the complete Non self canonical guide for every platform and the full background.