What is the Offer type in Schema.org?

In the markup of a product page, Offer answers two questions the product does not: what it sells for and whether you can buy it today. It is a type from Schema.org, and its name is a vocabulary term, not a plain word. It has nothing to do with an offer in the sense of a discount: a shirt at its regular price has an Offer too. And it is not the product, which has its own type, Product. It matters because it is the part of your structured data Google needs to show the price in rich results, and the part that drifts most often: every markdown and every stock change leaves it stale unless it is updated at the same time as the page.

How it works

Schema.org defines Offer as an offer to transfer some rights to an item or to provide a service, with examples such as selling tickets, renting a movie, repairing a motorcycle or lending a book. Unless something else is stated, an Offer is understood as an offer to sell.⁠^{[1]Schema.org. Offer} On a product page, the product carries it inside the offers property.

The properties that matter in a store, according to Schema.org:⁠^{[1]Schema.org. Offer}

Google takes that vocabulary and sets its own minimums. For merchant listings, the offer has to carry a price above zero and the currency as a three-letter ISO 4217 code. It also recommends availability, with values such as https://schema.org/InStock, OutOfStock, BackOrder or PreOrder; the condition, such as https://schema.org/NewCondition; the price validity date; shipping details; the return policy, with the MerchantReturnPolicy type; and the URL the item can be bought from.⁠^{[2]Google Search Central. Merchant listing (Product, Offer) structured data}

There is one more condition that is not in the vocabulary. Merchant listings accept only Offer, not AggregateOffer, because to qualify the merchant has to be the one selling the product. Product snippets, by contrast, accept both.⁠^{[2]Google Search Central. Merchant listing (Product, Offer) structured data} For them the price is required if you use Offer, the currency is recommended, and Google warns that the snippet may not show if priceValidUntil is a date in the past.⁠^{[3]Google Search Central. Product snippet (Product, Review, Offer) structured data}

And one warning that applies almost only to Offer. Google can read structured data added with JavaScript, but it warns that dynamically generated markup can make Shopping crawls less frequent and less reliable, a problem for things that change fast, like price and availability.⁠^{[4]Google Search Central. Generate structured data with JavaScript}

In a store

The offer for a shirt on sale, with what the page shows and how it is written in the markup. Fictional example: the store, the product, the price and the dates are made up.

"offers": {
  "@type": "Offer",
  "price": "29.90",
  "priceCurrency": "USD",
  "availability": "https://schema.org/InStock",
  "itemCondition": "https://schema.org/NewCondition",
  "priceValidUntil": "2026-10-31",
  "url": "https://www.example.com/calella-linen-shirt"
}

Three things the example shows. The price in the offer is the one the customer pays today, the discounted one, because the data has to represent the page as it is.⁠^{[5]Google Search Central. General structured data guidelines} The validity date is only set if the page states one; here the sale has an announced end. And availability is an address in the vocabulary, not the phrase the customer reads: "Only a few left" or "Ships in 48 hours" have no equivalent value, so you mark the fact (it is in stock) and leave the rest on the page.

How to check it

1. Search for offers in the page source of the product page and note the price, the currency and the availability it declares.
2. Compare them with what a customer sees at that moment, sale price included. If they do not match, the data does not represent the page.⁠^{[5]Google Search Central. General structured data guidelines}
3. Look at the priceValidUntil date, if there is one. If it has passed, the product snippet may not show.⁠^{[3]Google Search Central. Product snippet (Product, Review, Offer) structured data}
4. Check whether the offer is in the HTML the server sends or whether JavaScript adds it afterwards: for price and availability, Google warns that the second makes Shopping crawls less frequent and less reliable.⁠^{[4]Google Search Central. Generate structured data with JavaScript}
5. Run the URL through the Rich Results Test to see which experiences it detects and with what errors.⁠^{[6]Search Console Help. Rich Results Test}

Related concept: AggregateOffer

AggregateOffer is the type Schema.org proposes when one product has several offers, for example the same pair of shoes sold by different shops, and it sums up the set with the lowest price (lowPrice), the highest (highPrice) and the number of offers (offerCount).⁠^{[7]Schema.org. AggregateOffer} It fits a comparison site or a marketplace; on the product page of a store that sells its own goods, Offer is the right type, and Google accepts only Offer for merchant listings.⁠^{[2]Google Search Central. Merchant listing (Product, Offer) structured data}

To keep going, the structured data reading path puts the other terms in order, and the JSON-LD entry shows where this offer sits inside a product page's block.