When you set a category on a Shopify product, a new group of fields appears underneath it. Those are category metafields. This guide explains what they are, where their values come from, and what happens to them when a product's category changes.
What category metafields are
Category metafields map to specific product categories in Shopify's Standard Product Taxonomy, where they are called product attributes. Shopify's example is the category Apparel & Accessories > Clothing > Clothing Tops > Shirts, whose attributes include clothing size, neckline and sleeve length type.
- Tied to the category: A shirt and a sofa get different fields
- Purpose: Shopify says they help make products more discoverable on your site, on marketplaces and on search engines
Default and suggested fields
Not every attribute shows up in the same way. According to Shopify's help center, some category metafields are added by default based on AI predictions, and others might be suggested so you can choose whether to add them to your store.
| Kind | What happens |
|---|---|
| Default | Added to the product when the category is set |
| Suggested | Offered to you, and you decide whether to add it |
Entries and base values
A category metafield is filled by choosing an entry, not by typing free text. Each field comes with default entries that you can use as they are or customize. Shopify's example is renaming the color "black" to "graphite" to fit your branding.
- Select an entry: In the Category metafields section of the product, click the field and pick from the list
- Add your own: Click Add new entry, fill in the fields, then save
- Base values: Each entry has base values that connect it to Shopify's standardized list
- Variant options: Fields can be connected to variant options, so editing an entry updates every variant that uses it
What happens when the category changes
Changing a product's category does not wipe everything. Shopify states that category metafields with values, and those connected to variant options, are assigned to the new product category. Fields without values or variant connections are not carried over automatically.
- Kept: Fields with values, and fields connected to variant options
- Not carried over: Empty fields with no variant connection
Limits to know
The attribute list is fixed by the taxonomy. Shopify's help center lists these limitations at the time of writing.
- Custom attributes: Not supported. For your own fields, use regular metafields
- Units and dimensions: Unit of measurement and dimension type attributes are not currently available
Category metafields can also be used as filters and dimensions in Shopify analytics. Shopify's example is adding the Material metafield as a dimension in the total sales report. For when to use a metafield and when a tag will do, see Shopify metafields vs tags.
Doing this at scale
TaxonomyForge scans your catalog for missing categories and empty attributes. It proposes a Shopify Standard Product Taxonomy category with a confidence score and attribute metafields (material, color, style, occasion) drawn from your own copy, and you approve each change one by one or in bulk. See TaxonomyForge.