Custom field

What is a custom field?

A custom field is a user-defined data field that adds structured information to a resource beyond its standard fields. In Shopify it is called a metafield and can be attached to products, variants, collections, customers, orders, and pages. Each metafield has a namespace and key (e.g. custom.material) and a fixed data type such as single_line_text_field, integer, boolean, date, or a metaobject reference that validates the content.

Why does a custom field matter?

Shopify’s standard fields do not cover everything a catalog needs: material, fit, warranty, allergens, or lead time. Custom fields let you store exactly that data in a structured way in one place instead of cramming it into the product description as loose text. That makes the information reusable — it can be shown in the theme, used for filtering, passed into a product feed, and included in structured data without manual duplication.

Common use cases

• Add product specifications like material, dimensions, or weight to display in a clean table on the product page.
• Enrich product variants with data such as a color code or supplier SKU.
• Give visitors filtering on attributes that do not exist as a standard field.
• Store B2B or customer-specific data on customer profiles, e.g. a VAT number or discount tier.
• Feed advertising and price-comparison feeds with fields the channels require.

Shopify perspective

Always create a metafield definition in the admin rather than loose fields — the definition adds an editable, validated field to the editor and makes the value available to the theme. In Liquid you access it with e.g. product.metafields.custom.material.value (remember .value). If the fields are used for filtering, connect them through the Search & Discovery app. For reusable content made up of several fields, use metaobjects instead of a single custom field.