BigCommerce

BigCommerce's Stencil themes emit reasonable product markup and the platform generates a sitemap. The pattern of failure matches Shopify closely.

If you have a lot of products

Every fix below goes in the theme, not on individual products. Add Product schema to the product template once and it applies to your whole catalogue — twelve items or twelve thousand. The exceptions are alt text and product descriptions, which are per-item and best handled through a CSV export rather than one at a time.

Site-wide schema

Edit templates/layout/base.html in your Stencil theme and add before </head>:

<script type="application/ld+json">
{
  "@context": "https://schema.org",
  "@type": "Organization",
  "@id": "{{settings.base_url}}/#org",
  "name": "{{settings.store_name}}",
  "url": "{{settings.base_url}}"
}
</script>

If you cannot edit the theme, use Storefront → Script Manager to inject into the head on all pages.

Category descriptions

Products → Product Categories → [category] → Description. Same principle as Shopify: state who the category is for and what distinguishes the products in it. Then confirm your theme renders {{category.description}}.

Product alt text

Set on each image in the product editor. BigCommerce falls back to the product name, which is better than nothing but describes none of what is actually visible.

robots.txt

Settings → Data Solutions → Search Engine Optimization → robots.txt on newer plans, otherwise via the storefront settings. Add the AI crawler allows.

Faceted navigation

BigCommerce's filtered category URLs can generate large numbers of near-duplicate pages. Make sure canonical tags point at the unfiltered category, or you dilute the signal across dozens of thin variants.