How should the indexing of product variants be managed in e-commerce?

Short answer: The decision rests on one question: does the variant have search demand of its own? If people type the color or capacity into their query, that variant deserves its own indexable URL; if they do not, canonicals consolidate all variants onto a single product page.

Two models, one criterion

TYS Digital Performance makes this call with query data rather than assumptions: when the variant attribute (color, size, capacity) appears in search terms, the separate-page model applies; otherwise the consolidated model wins.

• Consolidated: variant selection happens on one URL; parameterized alternatives point their canonical at the main page.
• Separate pages: each variant needs its own title, imagery, and description; duplicated copy defeats the purpose of a separate URL.
• Mark up price, availability, and variant attributes correctly in Product structured data.
• Include only the versions you want indexed in the sitemap.

Do not delete out-of-stock variants immediately: keep the page if stock returns, redirect to the closest alternative if it is gone for good. Verify decisions through indexing reports and organic entrances.