Out-of-stock SEO and structured data
for ecommerce

The four schema.org availability values you actually need

Schema.org's ItemAvailability enumeration has 14 values, but only four matter for AI shopping agents in 2026. Using the wrong one costs you either in AI agent visibility (unavailable products surfaced as buyable) or in conversion quality (back-orderable products hidden entirely).

The most expensive mistake: using OutOfStock for back-orderable items

Shopify's default theme outputs OutOfStock for any product where product.available == false. But a product with inventory_policy: continue (the "Continue selling when out of stock" setting) is actually back-orderable — the merchant intends to accept orders and fulfill them when stock arrives. Using OutOfStock here causes:

• ChatGPT Shopping to hide the product from transactional queries
• Google Shopping to suppress it from in-stock filters
• Google AI Mode to not show the "ships by" date it would show for BackOrder
• Perplexity to display "unavailable" when the product is actually orderable

AI agent behavior by availability value

Correct Liquid JSON-LD for all availability states

Complete availability detection snippet (Shopify Liquid)

{% assign variant = product.selected_or_first_available_variant %}
{% assign avail_url = "https://schema.org/" %}

{% if variant.available %}
  {% assign availability = "InStock" %}
{% elsif variant.inventory_policy == "continue" %}
  {% comment %} Continue selling = back-orderable {% endcomment %}
  {% assign availability = "BackOrder" %}
{% elsif product.tags contains "pre-order" or product.tags contains "preorder" %}
  {% assign availability = "PreOrder" %}
{% elsif product.tags contains "discontinued" %}
  {% assign availability = "Discontinued" %}
{% else %}
  {% assign availability = "OutOfStock" %}
{% endif %}

<script type="application/ld+json">
{
  "@context": "https://schema.org",
  "@type": "Product",
  "name": {{ product.title | json }},
  "offers": {
    "@type": "Offer",
    "availability": {{ avail_url | append: availability | json }},
    "price": {{ variant.price | divided_by: 100.0 | json }},
    "priceCurrency": {{ shop.currency | json }},
    "url": "{{ shop.url }}{{ product.url }}"
    {% if availability == "BackOrder" and product.metafields.custom.restock_date != blank %}
    ,"orderDeliveryTime": {
      "@type": "ShippingDeliveryTime",
      "handlingTime": {
        "@type": "QuantitativeValue",
        "minValue": 0,
        "maxValue": {{ product.metafields.custom.restock_days_min | default: 7 }},
        "unitCode": "DAY"
      },
      "transitTime": {
        "@type": "QuantitativeValue",
        "minValue": 2,
        "maxValue": 5,
        "unitCode": "DAY"
      }
    }
    {% endif %}
    {% if availability == "PreOrder" and product.metafields.custom.release_date != blank %}
    ,"availabilityStarts": {{ product.metafields.custom.release_date | json }}
    {% endif %}
  }
}
</script>

BackOrder with explicit delivery window

For back-orderable items, Google AI Mode and ChatGPT Shopping both surface the expected delivery date when you pair BackOrder with a proper OrderDeliveryTime block. This drives measurably higher click-through than a bare "back order" label.

{
  "@context": "https://schema.org",
  "@type": "Product",
  "name": "Titanium Water Bottle 32oz",
  "offers": {
    "@type": "Offer",
    "availability": "https://schema.org/BackOrder",
    "price": 49.00,
    "priceCurrency": "USD",
    "availabilityEnds": "2026-07-15T00:00:00-05:00",
    "orderDeliveryTime": {
      "@type": "ShippingDeliveryTime",
      "handlingTime": {
        "@type": "QuantitativeValue",
        "minValue": 14,
        "maxValue": 21,
        "unitCode": "DAY"
      },
      "transitTime": {
        "@type": "QuantitativeValue",
        "minValue": 2,
        "maxValue": 5,
        "unitCode": "DAY"
      },
      "businessDays": {
        "@type": "OpeningHoursSpecification",
        "dayOfWeek": [
          "https://schema.org/Monday",
          "https://schema.org/Tuesday",
          "https://schema.org/Wednesday",
          "https://schema.org/Thursday",
          "https://schema.org/Friday"
        ]
      }
    }
  }
}

PreOrder with launch date

{
  "@context": "https://schema.org",
  "@type": "Product",
  "name": "Model X Pro Headphones — 2026 Edition",
  "offers": {
    "@type": "Offer",
    "availability": "https://schema.org/PreOrder",
    "availabilityStarts": "2026-09-01T09:00:00-07:00",
    "price": 299.00,
    "priceCurrency": "USD",
    "priceValidUntil": "2026-12-31"
  }
}

Shopify inventory_policy: the hidden back-order signal

The most overlooked Shopify availability signal is variant.inventory_policy. When a merchant enables "Continue selling when out of stock" in the product variant inventory settings, Shopify sets this field to "continue". The default Dawn theme completely ignores this and outputs OutOfStock regardless.

In CatalogScan's scan data, 34% of stores that accept back-orders output OutOfStock in their JSON-LD, causing AI agents to suppress products the merchant is ready and willing to sell.

Keeping availability in sync via webhooks

Availability values in JSON-LD must match actual inventory state. AI agents do not appreciate discovering a product marked InStock in structured data that is actually sold out on the product page — it erodes trust scores and can trigger content quality penalties in Google Search. The cleanest approach for high-volume stores is a webhook that updates the product page's availability metafield in near real-time.

// Shopify webhook: inventory_levels/update
// Node.js handler
app.post('/webhooks/inventory', shopifyWebhookMiddleware, async (req, res) => {
  const { inventory_item_id, available } = req.body;

  // Look up which product variant owns this inventory item
  const variant = await shopify.rest.Variant.all({
    session,
    inventory_item_ids: inventory_item_id
  });

  if (!variant?.data?.length) return res.sendStatus(200);

  const v = variant.data[0];
  const policy = v.inventory_policy; // 'deny' or 'continue'

  let availability;
  if (available > 0) {
    availability = 'InStock';
  } else if (policy === 'continue') {
    availability = 'BackOrder';
  } else {
    availability = 'OutOfStock';
  }

  // Store in metafield so Liquid template can read it
  await shopify.rest.Metafield.save({
    session,
    body: {
      metafield: {
        owner_resource: 'product_variant',
        owner_id: v.id,
        namespace: 'catalog_scan',
        key: 'availability',
        value: availability,
        type: 'single_line_text_field'
      }
    }
  });

  res.sendStatus(200);
});

SEO strategy for permanently out-of-stock pages

When a product is discontinued or permanently removed, you have three options:

1. Keep the page live with Discontinued availability — maintains any accumulated backlinks and lets AI agents understand the product exists but is gone. Add internal links to the closest in-stock alternatives. Best for high-traffic product pages.
2. 301 redirect to the closest in-stock alternative — transfers link equity and prevents AI agents from surfacing the dead product. Best for products with a clear direct replacement.
3. 301 redirect to the parent collection — least disruptive for generic products with no clear replacement. Ensures users land on relevant inventory rather than a dead end.

Never serve a 410 Gone for a product page that has existing inbound links from editorial coverage or AI citation lists. The 410 immediately signals "this no longer exists" and purges the page from AI agent knowledge bases, destroying any earned AI-citation authority permanently.

Scan for availability mismatches

CatalogScan's free scan checks whether your product JSON-LD availability values match your actual Shopify inventory state, flags back-orderable products incorrectly marked OutOfStock, and identifies products using InStock while the add-to-cart button is disabled.

Scan your store free

Related: Subscription product availability · Schema markup guide · Metafields and AI agents