id is the unique, permanent name of a product (or variant) inside your Merchant Center account: up to 50 characters, case sensitive, used once, and never changed, because Google ties the product’s approval history and performance to it. The platform’s variant id or a stable SKU is the right value; a URL or a title is not.
| Attribute | id |
|---|---|
| Requirement | Required for each product. |
| Format |
|
Google’s rules for id
- Use a unique value per product and never reuse an id for a different product.
- Keep the same id over time: a changed id is a new product to Google, with no history.
- Avoid whitespace and symbols that need encoding; letters, digits and simple punctuation are safe.
- Within one account and target country, the same id in two feeds is the same product, and the later feed overwrites the earlier.
Common mistakes, and the error each one becomes
- The parent product’s id written on every variant row. → Reused value [id]
- A URL or a title used as the id, past 50 characters. → Product ID too long
- Ids regenerated on each export, so history resets every time.
Where the value comes from on a connected store
| Shopify | The variant id, a short permanent number, with the product id as item_group_id. |
|---|---|
| WooCommerce | The variation’s post id (or the product’s, for simple products), which never changes; the parent id becomes item_group_id. |
The free feed check reads this attribute from any feed file and reports the defects above; every check is listed.
Questions merchants ask
Should the id be the SKU?
If every variant has a distinct SKU that never changes, yes. If SKUs are renamed or shared, the database variant id is safer, because the id must be stable for the life of the product.
What happens if I change all my ids?
Google sees every product as new: approval history and performance data start from zero. Do it once, for a good reason, and never again.
Can two variants share an id?
No. Each variant is a product to Google and needs its own id; variants of one product share item_group_id instead.
Sources
- ID [id] — Google Merchant Center Help
- Product data specification — Google Merchant Center Help