In other words: when should you keep products on their own individual pages, and when should you put multiple products on the same page together?
What makes the best SEO sense will vary from store to store. This isn’t a black-and-white, one-right-way kind of situation, but we’ll preview the overall logic and let you get the full details from the link.
Starting off simple: you’d just want the solo product page for any product that “is what it is,” without variants or options. If you only sell Doohickeys—one thing, one type, take it or leave it—category pages would be very silly.
Still simple, but on the other side of the spectrum: if you sell a Home Depot’s worth of products, please dear lord get some category pages in there too. The more products you sell, the more they need to be grouped and organized and even “curated” for the customer.
Things get a bit blurrier once you add product variants into the mix.
If you’re selling one T-shirt but in multiple sizes, you’d still want just the single product page because shirt size isn’t a meaningful variation. In other words, it doesn’t affect how you’d present the shirt on the page, and it doesn’t present any real choice to the consumer (either you have their size or you don’t). Still no use for category pages yet.
But suppose that you expand your line and later offer numerous different T-shirts, each in multiple colors AND multiple sizes. Naturally, each design of shirt will have its own focused product page which includes the variants you offer for it. But at some point, you should also create category pages which collect together different shirts and shirt variants. (Maybe the graphic tees get their own page. Or the black tees get a page. Or… you get it.)
Two final guiding thoughts:
1️⃣ Category pages allow you to present meaningful groupings of products that the customer would want to see together in one place—and because each category page is separate, you get to customize each one to its unique selling needs (which could help boost revenue metrics like AOV).
2️⃣ Be judicious, though, because category pages ain’t free. (Neither are individual product pages, but we assume you already have those up, because how are you selling those products otherwise?)
It takes time, money, and/or manual effort to get category pages built, and it takes more of the same to maintain them in the long run. The SEO doesn’t have to cause you big headaches here, but that’s likelier to happen the longer you keep going (and growing) without a big-picture idea of how you’re managing your products and their pages.