How Does WooCommerce Decide Which Related Products to Show?

How the Default WooCommerce Logic Works

WooCommerce's core related products query looks at the current product's assigned categories and tags, then pulls a random selection of other published products sharing at least one of those, excluding the current product itself. This is a reasonable, low-effort default, but it doesn't account for actual purchasing patterns ("customers who bought X also bought Y") the way a more sophisticated recommendation system would.

Why This Sometimes Produces Odd Results

• A very broad or loosely defined category can produce related products that feel only tangentially connected, since the matching logic is purely categorical, not based on deeper product similarity or actual customer behavior.
• A product with unique categories/tags not shared by anything else in the catalog may show no related products at all, or fall back to a broader, less relevant match.
• Cross-sells (covered elsewhere) are a separate, manually curated mechanism — if genuinely relevant, hand-picked suggestions matter, cross-sells (or upsells) offer more control than relying on the automatic related products logic.
• Plugins exist specifically to improve this with behavior-based recommendations (actual co-purchase data) rather than the simple category/tag matching WooCommerce ships with by default.

Improving Related Product Suggestions

1. Review category/tag structure to ensure related products logic has meaningful groupings to draw from.
2. Use manually curated cross-sells or upsells where genuine control over specific suggestions matters more than automatic matching.
3. Consider a behavior-based recommendation plugin for a more sophisticated, purchase-pattern-driven approach.

Need smarter product recommendations built for your store? See custom WooCommerce development.