Feed attribute

custom_label_0

Custom label

The custom_label attributes are five free-text fields, numbered 0 to 4, that carry your own segmentation into a feed so campaigns can bid on groupings the channel knows nothing about. Nothing is shown to shoppers: their entire purpose is to let you subdivide a catalogue by margin, season, stock age, bestseller status or anything else you can compute.

Specification

Attribute: custom_label_0
Data type: Text
Limit: 100 characters
Format: Free text, but treat it as a controlled vocabulary rather than a description. Values are matched exactly and case-sensitively when building campaign groupings, so a handful of consistent tokens such as high_margin or clearance is far more useful than descriptive prose. Each item may hold one value per label, across five independent labels.
Examples: high_margin clearance aw25 bestseller

Support by channel

How each channel treats custom_label_0.

Channel	Requirement	Field name	Notes
Google Shopping	Optional	custom_label_0	Five labels available, custom_label_0 through custom_label_4.
Microsoft Advertising	Optional	custom_label_0
Meta	Optional	custom_label_0	Supported for catalogue segmentation in Advantage+ campaigns.
OpenAI	Optional	ads_metadata	There is no custom_label_0. Custom labelling for Ads is carried under ads_metadata instead.

Frequently asked questions

What are custom labels used for?

They subdivide a catalogue for campaign management. Because they are invisible to shoppers, they can encode anything useful for bidding: margin band, season, stock age, bestseller status, or whether an item is on promotion. Campaigns then target those groupings directly.

How many custom labels can I use?

Five per item, custom_label_0 through custom_label_4, each holding one value. They are independent, so one can carry margin band while another carries season.

How do I derive custom labels from Shopify?

They are almost always computed rather than stored. Typical sources are a conditional rule on price or margin, a metafield, tag membership, collection membership, or a comparison between cost and price. Anything you can evaluate per variant at generation time can become a label.

Related attributes

sale_price The sale_price attribute is the temporarily reduced price of an item, submitted alongside the full price so a channel can show the reduction rather than simply a lower number. On Shopify the reliable source is the variant's compare-at price relationship, and discounts applied by code or automatic rule are not visible in the product record at all.

Related concepts

Product feed A product feed is a structured file listing every item a shop sells, with one row per purchasable item and one column per attribute the destination understands. Sales channels use it to build their own copy of a catalogue, which is why a feed is a translation of a shop's data into another system's schema rather than an export of it.

Primary sources

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

Google: custom_label attribute specification

Last reviewed 16 September 2026 View as markdown