# 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.

- **Canonical URL:** https://www.feedlab.io/knowledge/attributes/id
- **Last reviewed:** 16 September 2026
- **Source:** feedlab knowledge base
- **Licence:** free to quote and cite with attribution to feedlab


## Specification

| Property | Value |
| --- | --- |
| Attribute | `id` |
| Plain name | Product 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. |


### Example values

- `shopify-44219834`
- `TSHIRT-BLK-M`
- `9781234567897`



### Support by channel

| 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.




## Primary sources

- [Google: id attribute specification](https://support.google.com/merchants/answer/6324405)