Check Product and Offer structured data

Reads product pages and checks their Product and Offer JSON-LD against what Google's merchant listings need — errors: name, image, offers as Offer (not AggregateOffer) with a price above 0 and an ISO 4217 priceCurrency (or a priceSpecification), a valid availability; warnings: brand (its name not empty or N/A), a GTIN or MPN or SKU, description, offers.url, itemCondition, priceValidUntil when it has passed, validFrom without an end date, shipping details with shippingDestination and deliveryTime, a return policy with applicableCountry and returnPolicyCategory, a rating with ratingValue and reviewCount, hasAdultConsideration values, a ProductGroup's productGroupID, variesBy and hasVariant, and with eu: true the energy efficiency class; notes: returnPolicyCountry, member programs, variants — says whether each page is eligible, and gives a completenessScore (required fields 50, aggregateRating 65, an identifier 75, shippingDetails 85, a return policy 90, three or more reviews 100). With no urls, the latest crawl's pages that carry Product markup (up to limit). render 'auto' renders a page in a browser when its HTML carries no Product markup, for stores that inject their JSON-LD with JavaScript. Answers 'is our product schema right' and 'why don't our products show prices in Google'. Free.