If L disappears after a color change, shoppers may think it is never sold.
Unavailable sizes: explain status and alternatives
Keep unavailable sizes visible and explain why they cannot be selected. Backorders need separate wording.
Research context: Baymard · Product-list information ↗
Show status for each color/size pair. Offer stock alerts only when a working notification service is configured.
Try the pattern
Task and expected result
- 01
Choose brown Softy: L should remain visible as sold out.
- 02
Choose black XL: see backorder rather than in stock.
- 03
Switch to a color lacking the chosen size: request a new selection.
How to investigate value
Ask shoppers to explain their variant choice and fit. Later measure confirmed purchases per eligible product visitor, with return reasons as follow-up.
Watch for side effects
Wrong sizes, unknown details shown as facts, mismatched expectations and product-related support/returns.
This is a proposed investigation, not a measured result. Choose one hypothesis and define the audience before testing.
Build a measurement plan for this concept ↗