Product feed(GTIN/MPN)

Long definition

The feed is the source of truth for everything Google shows in Shopping surfaces. Get it right and your products appear in the Shopping tab, free listings, popular-products carousel, and paid Shopping ads. Get it wrong and they're either disapproved (invisible) or approved with bad data (worse — wrong price, wrong stock, returns).

Required attributes for any retailer feed in the US/EU, per the Merchant Center help: id (unique SKU identifier, stable over time), title (≤150 chars, the first 70 carry the weight), description (≤5000 chars), link (PDP URL, must match the canonical), image_link (≥250×250 px, no watermarks or promotional overlays), availability (in_stock, out_of_stock, preorder, backorder), price (with ISO currency code), brand, and one of gtin or mpn.

GTIN vs MPN. GTIN (Global Trade Item Number) — the umbrella for UPC, EAN, JAN, ISBN — is the universal product identifier and Google strongly prefers it. MPN (Manufacturer Part Number) is the fallback when no GTIN exists, used with brand. Products without identifiers get the identifier_exists: false flag, but only certain custom-made categories qualify for that exemption — apparel without GTIN gets disapproved.

Image rules. Square or portrait, white or transparent background, no text overlays, no promotional badges, no watermarks. Apparel products should show the item against a plain background; lifestyle shots are accepted as additional images via additional_image_link. Image fetching is asynchronous — a CDN that 503s during Google's fetch window will silently disapprove the product.

Freshness. Feeds expire. The default expiration is 30 days from upload; Merchant Center recommends a fetch schedule of every 1-7 days, and any product not refreshed within 30 days gets dropped. For volatile catalogs (price/stock change frequently), Content API push or supplemental feeds keep specific attributes fresh between full uploads.

Supplemental feeds let you layer overrides on top of a primary feed without rebuilding the whole catalog. Useful for promotions, custom labels, or fixing specific attributes flagged by the diagnostics report.

Common misconceptions

• "The feed is just for paid ads." It powers Shopping ads, free Shopping listings, the Shopping tab, and product modules in regular Search. The feed is required for every product surface in Google Shopping.
• "On-page schema and feed can disagree." They can technically. They shouldn't. Disagreement triggers manual review, lowers trust, and in repeated cases gets the account suspended for misrepresentation.
• "GTIN is optional for big brands." No. Even Nike sneakers need GTIN for full eligibility. The exemption is narrow: handmade, custom, vintage, or pre-1995 products without a manufacturer-assigned identifier.
• "Image overlays boost CTR." Overlays violate Merchant Center policy. The product gets disapproved; CTR is moot when the listing isn't running.