If you sell clothing, shoes, phone cases or anything else that comes in sizes and colours, you will meet product variants on day one. The question is simple: should a blue T-shirt in size M be its own product, or one option of a bigger product?
Get it wrong and your catalog fills with near-identical pages, buyers scroll past the same item twelve times, and your stock counts end up split across products that are really one thing. This guide explains how product variants work, how to plan them, and when a version does deserve its own page.
What a product variant is
A product is the thing a buyer recognises: "Classic Cotton T-Shirt". A variant is one specific version they can put in the cart: the Classic Cotton T-Shirt in blue, size M.
Each variant is a separate sellable item, usually with its own SKU code, its own stock count and, if you want, its own price. The buyer sees one product page with a size selector and a colour selector, picks a combination and adds exactly that item to the cart.
The opposite approach, one product per combination, creates duplicate products.
Why duplicate products cause problems
- A cluttered catalog. Buyers see the same photo and title many times and find it harder to compare different items.
- Split reviews and content. Reviews, descriptions and photos are spread across several pages instead of building up on one.
- Competing pages in search. Several pages with almost the same text compete with each other instead of one strong page.
- Messy stock. It is harder to see at a glance how many of the model you have in total and which size runs out first.
Options, values and combinations
Variants are built from options (sometimes called attributes or axes) and their values:
- Option: Size. Values: S, M, L, XL.
- Option: Colour. Values: Black, White, Blue.
The number of variants grows by multiplication:
Number of variants = values of option 1 × values of option 2 × ...
Example: a phone case made for 5 phone models in 4 colours is 5 × 4 = 20 variants of one product. Add a third option such as Strap (with or without, 2 values) and you get 40.
That is why it pays to define options once and reuse them across products, instead of typing values by hand on every item. "Size" should mean the same thing everywhere in your store, and "Blue" should not appear as "blue", "Blu" and "Navy-ish" on different products.
Each variant also needs its own code; How to Create a SKU System for Your Products shows how to build one.
Not every combination has to exist. If the white version only comes in S and M, create only those variants. A missing variant is better than one that always shows "out of stock".
Variant options vs product characteristics
Not every property should create variants. A useful test: does the buyer receive a different physical item when the value changes?
- Size, colour, capacity, length: yes, the item on the shelf is different. These are variant options.
- Material, weight, care instructions, warranty period: no, they describe the product. These are characteristics, shown in a specification list.
Mixing the two is a common mistake. If you make "Material: cotton" an option, you create variants that do not need separate stock, which only adds noise.
When a version deserves its own product page
Variants work best when versions differ only in size or colour and share the same photos, description and story. Sometimes that is not true:
- the versions look very different and need their own photo sets;
- each version has its own description, such as a print with its own name;
- you want each version to be found on its own in search.
In that case, create separate products and link them together so buyers can switch between versions from the product page. You keep separate pages without leaving buyers to hunt for the other colours.
Example: one hoodie set up three ways
Here is an example with made-up numbers. A small shop sells a hoodie in 3 colours (black, grey, green) and 4 sizes (S to XL).
Option A, duplicate products: 12 product pages. A typo in the fabric description has to be fixed 12 times. The shop owner cannot see quickly that 9 of the 12 pages are a single model.
Option B, variants: 1 product page with 12 variants. One description, one set of reviews, stock per variant. The owner sees at once that size M in black has 2 left and green XL has 15.
Option C, a mix: the green hoodie is a collaboration print with its own photos and story, so it becomes a separate product with 4 size variants, linked to the main hoodie by colour. The main product keeps 8 variants for black and grey.
Option C is often the most practical: variants for routine differences, separate linked products where the story is different.
Pricing and stock per variant
Variants can have different prices when there is a real reason, such as an XXL that uses more fabric. Stock should always be counted per variant: "20 hoodies in stock" is useless if all 20 are size S.
A variant setup checklist
- [ ] List the options that really change the item (size, colour, capacity).
- [ ] Define each option once with fixed value names.
- [ ] Keep descriptive properties as characteristics, not options.
- [ ] Create only the combinations that exist.
- [ ] Decide per product whether versions are variants or linked separate products.
- [ ] Check prices and stock per variant before publishing.
How RedCart handles variants
In the RedCart Store module, you create options such as Size or Colour once at store level, with their values. On each product you tick the values it actually comes in, and when you save, the cabinet builds one SKU for each combination of the ticked values. Colour values are picked with a colour picker, so each one carries a real colour, not just a word.
Every option is either a SKU axis or a characteristic, so material or weight stay descriptive and do not multiply SKUs. Each SKU can carry its own price, and stock is kept per SKU in each warehouse. When versions need their own pages, product families link separate products by a characteristic such as colour, with switches on the product page, while each card keeps its own URL and you choose which one appears in the catalog.
Key takeaways
Treat sizes and colours as variants of one product, define options once, create only real combinations, keep descriptive details as characteristics, and give a version its own linked page only when its photos and story are different.
If you would like to set up your sizes and colours with us, create a RedCart account.