Feed attribute

id

Product ID

The id attribute is the unique, permanent identifier a sales channel uses to recognise one item across every feed update. In a Shopify feed it must identify a single variant rather than a product, and once a channel has seen an id it should never be reused for a different item.

Specification

Attribute: id
Data type: Text
Limit: 50 characters
Format: Unique within the feed, stable across regenerations, and made only of valid Unicode characters. Leading and trailing whitespace is not allowed. The value is case-sensitive on most channels, so treat SKU-1 and sku-1 as different items.
Examples: shopify-44219834 TSHIRT-BLK-M 9781234567897

Support by channel

How each channel treats id.

Channel	Requirement	Field name	Notes
Google Shopping	Required	id	Cannot be changed without losing the item's performance history.
Meta	Required	id	Called "Content ID" in Commerce Manager and in pixel events.
Microsoft Advertising	Required	id
Pinterest	Required	id
OpenAI	Required	item_id	Called item_id. Variants are submitted as one row each, so every variant carries its own item_id.

Frequently asked questions

Should the feed id be the Shopify product ID or the variant ID?

It should be the variant ID. Channels treat each row as a separately purchasable item, and a Shopify product with three sizes is three items. Using the product ID collapses all variants into one row and loses the size and colour a shopper filters on.

What happens if I change a product's id in the feed?

The channel treats it as a brand new item. The old id is dropped from the catalogue and the new one starts from zero, losing accumulated performance history and any review or ranking signals attached to it. Ids should be treated as permanent.

Can I use the SKU as the feed id?

Yes, provided every variant has a SKU, the SKUs are unique across the whole catalogue, and they never get edited. In practice Shopify SKUs are frequently blank or reused, so the variant ID is the safer source.

Errors involving this attribute

Duplicate product id A duplicate id error means two or more rows in a feed claim the same identifier, so the channel cannot tell which one describes the item and keeps only the last it processed. On Shopify it usually means the feed was built per product rather than per variant, or that a SKU used as the id is blank or reused across variants.

Related attributes

item_group_id The item_group_id attribute groups the rows that are variants of the same product, so a channel can show one listing with a size or colour picker instead of several unrelated listings. On Shopify the natural source is the product ID, shared by every variant row generated from that product.

Related concepts

Variant-level feed A variant-level feed emits one row for each purchasable variant rather than one row per product, because sales channels treat every size, colour and material as a separately buyable item with its own price, stock and barcode. A Shopify product with four sizes in three colours is one product in the admin and twelve items to a channel.

Primary sources

Channel specifications change. These are the official documents this page is based on.

Google: id attribute specification

Last reviewed 16 September 2026 View as markdown