Custom labels

Custom labels are five attributes in a product feed, custom_label_0 to custom_label_4, that you fill with your own text to group products in campaigns.

By Berend Vrakking, founder of Product Metrics. Updated 7 October 2026.

Example

Three products and their label
Product	custom_label_0	What you can do
Trail Runner 2	stars	Increase priority
Winter Boot	dogs	Lower priority
Everyday Sock	cash_cows	Keep priority

A label groups products, and you decide what each group gets. The values here are the segment names Product Metrics writes; you can use your own values. Illustrative data.

For one product, and for an account

A label lives on one product, so it lets you treat products differently inside one account. Google describes custom labels as a way to build filters for Performance Max, Shopping and Demand Gen campaigns, and to report and bid on groups of products.

Product Metrics ML puts each product in one of six segments, by volume and return, and writes the segment to a custom label through a supplemental feed. Performance Max asset groups can then split on the label.

Common mistake

Spending all five labels on colour and season when you need to steer by performance. A label that never changes cannot tell a campaign which products to increase or lower priority on.

Questions

How many custom labels can a product have?

Five, numbered custom_label_0 to custom_label_4. Google asks for one value in each label attribute, so a product has at most five labels, each holding a single value.

Can Performance Max use custom labels?

Yes. Google lists Performance Max, Shopping and Demand Gen campaigns as places to filter products by custom label.

What should I put in custom labels?

Values that describe how a product performs and that change when its performance does, such as a return group or a stock status. A campaign can then split products by the label and act on the split.

Sources

Google Merchant Center Help: Custom label [custom_label_0 - custom_label_4]

Keep reading

Google Merchant CenterWhere the product data and its labels live.
Product SegmentationSee each product in one of six segments, by volume and return.
Performance MaxSee spend and return per product segment and category.
Growth-share matrixThe matrix whose names Product Metrics also uses for segments, defined differently.
What is Google Merchant Center? An advertiser’s guideHow labels reach Shopping and Performance Max, with a worked example.
Performance Max for ecommerceUse custom labels to keep low-return products out of a campaign.
How to optimise Google Shopping adsSeven steps, with custom labels to set priority per product.