You fill category metafields in Shopify in two steps: first choose the right product category from the Shopify taxonomy in the product. Shopify then shows that category's attributes, such as color, material, size or target gender, and you pick the values from a fixed list. For variants you can link an option like "Color" directly to the metafield. That keeps the data structured and readable for filters, Google and AI assistants.
What category metafields are
Shopify maintains a standardized product taxonomy, a large tree of categories like "Apparel > Tops > Shirts". Each category comes with matching attributes. For a shirt these are, for example, color, material, size, sleeve length or neckline. Food has different attributes than furniture.
Shopify stores these attributes as category metafields. The difference from a free text field: the values come from a predefined list. "Sage" is mapped to the standard value "Green", for example. As a result, every system reading the data understands what is meant.
Why it is worth the effort
- Store filters: with Shopify's Search & Discovery app you can create filters based on these metafields, such as color or material.
- Sales channels: Shopify can pass structured product data to connected channels. Google gets clearer information than from a description text.
- AI assistants: when someone asks for "green linen shirt men", it helps if material, color and target group exist as clear values, not just somewhere in the body text.
Step 1: choose the right product category
- In Shopify admin, open Products and choose a product.
- In the Category field, Shopify often suggests a category already. Check the suggestion.
- Find the most specific matching category. "Shirts" is better than "Apparel", because only the specific category brings the matching attributes.
- Save the product.
Watch out: the product category is not the same as the product type. The product type is a free field for your own organization. The category comes from the Shopify taxonomy and determines the metafields.
Step 2: fill in the attributes
After saving, the product shows a section with the category metafields. Which fields you see depends on the category.
- Click a field, for example Material.
- Choose one or more values from the list. For a shirt made of 55% linen and 45% cotton, choose both materials.
- If your value is not in the list, take the closest standard value. For some attributes you can also add your own entries mapped to a standard value.
- Only fill fields you are sure about. An empty field is better than a wrong value.
Be especially careful with food and cosmetics. Only enter allergens, "vegan" or "gluten-free" if recipe, label or manufacturer information backs them up.
Step 3: link variant options
If your product has variants by color or size, you don't have to maintain the values twice. Shopify lets you link a variant option to the matching category metafield.
- In the product, open the Variants section and edit the option, for example Color.
- Choose to link it to the category metafield.
- Map each of your option values to a standard value, for example "Sage" to "Green".
The label in your store can stay your own. In the background sits the standard value that filters and channels understand.
Which attributes matter by industry
| Industry | Typical attributes | What to watch |
|---|---|---|
| Fashion | Color, size, material, target gender, age group | Link color and size as variant options |
| Home | Color, material, style, shape | Pick the main material, not every coating |
| Jewelry | Material, color, jewelry type | Only state precious metal for genuine alloys |
| Food | Dietary preferences, allergens, flavor | Only documented facts, never estimates |
| Cosmetics | Skin type, ingredient properties, scent | Use manufacturer information |
You see the exact attributes per category in Shopify itself once the category is set. The table is a guide, not a complete list.
Google fields are something else
For Google Shopping, apparel also needs age group, gender and, for used goods, condition. Depending on how your store is connected to Google, these values come from their own metafields, for example from the mm-google-shopping namespace at variant level, or from your feed app's settings. So check both: the category metafields and the Google-specific fields.
Faster with Heartly
Heartly's visibility score shows which products are missing a category or important attributes. The "Fix now" assistant (Beta, Shopify, paid plan) suggests the product category and values for the category metafields. The values come from the Shopify taxonomy, and the assistant does not guess allergens or dietary information. You review every suggestion before it is saved and can undo changes for 30 days. Age group, gender and condition for Google can also be set there as variant metafields.
Checklist
- Every product has the most specific product category possible.
- Color, material and size are set where the category offers them.
- Color and size options are linked to the metafields.
- Allergens and dietary information only appear where documented.
- Google fields like age group and gender are maintained for apparel.
- Search & Discovery filters use the new metafields.
Typical mistakes when filling them in
- Category too broad: with "Apparel" instead of "Shirts" you miss the specific attributes.
- Values only in the title: "green linen shirt" in the title doesn't replace the metafield. Systems reading structured data only see the title as text.
- Contradictions: the metafield says "cotton", the description "100% linen". Align both whenever you change one.
- Custom color names without mapping: a filter only understands "Midnight" if it is mapped to the standard value "Blue".
For an existing catalog, work category by category: first all shirts, then all trousers. That keeps values consistent within a group, and you see faster which attributes really matter there.
Frequently asked questions
Do I have to fill every category metafield?
No. Fill the fields that apply to your product and matter to customers. Color, material and size are the most important in many categories.
What happens if I change the category later?
The available attributes change with the category. After switching, check whether the values still fit and whether new fields appeared.
Do category metafields replace the product description?
No. Metafields provide structured facts, the description explains them for people. Both should match.
Can I manage category metafields via CSV?
The Shopify product export contains columns for the product category and for metafields. It works for larger catalogs but is error-prone. Test with a few products first.
Check your catalog
Want to know how many of your products are affected right now? The free visibility check works without installing anything. If you want to close the gaps directly in Shopify, Heartly is in the Shopify App Store ($19 per month, 14-day free trial).