# Graying Out vs Hiding Out-of-Stock Products A/B Test

Page: https://alidemirbas.com.tr/en/lab/ab-test-library/tests/graying-out-vs-hiding-out-of-stock-products-ab-test

## Hypothesis

If out-of-stock products are hidden, shoppers may reach in-stock items faster without stopping at cards they cannot buy, while gray styling keeps the category's full range visible. Hiding could come out ahead on the category-page purchase rate as the out-of-stock share grows; with a small share, the two options may barely differ.

## When to run this test

This comparison is worth planning when out-of-stock products fill a noticeable part of your category lists; session recordings of shoppers tapping grayed-out cards and backing out, site search clicks that land on sold-out items, or support tickets saying products are always sold out all point to it. If hiding wins, shoppers reach in-stock products faster; if graying wins, the wider assortment keeps them browsing. If the real issue is wrong stock data, fix that first, and check that the gray arm shows unavailable items as clearly not purchasable and that neither arm switches on a “show in-stock only” filter the shopper did not choose.

## Primary metric

**Category-page purchase rate**: Compare purchases among category visitors assigned to the two out-of-stock display approaches.

## Other metrics

- **Product detail click-through rate**: Compare visits to in-stock product pages between arms.
- **Category-page exit rate**: Track exits among visitors who see the category page.
- **Back-in-stock signup rate**: Track this only if a “notify me” flow already exists; do not add a new signup flow.
- **Listing load time**: Check whether stock-status and label handling affects load time.

## What to check before and during the test

- **Display**: Show the same out-of-stock products in gray in one arm and hidden in the other.
- **Keep constant**: Keep the order, filters and stock data for available products the same.
- **Purchases**: Compare purchases among all eligible visitors assigned to the category-page experience.
- **Out-of-stock share**: Record the share of products out of stock; eligibility should be comparable between arms.
- **Existing flow**: If a back-in-stock notification already exists, keep it the same in both arms.

## What to watch when reading the result

- The category-page purchase rate is what picks an option; product detail click-through, category-page exits and listing load time explain why it moved. More product page visits without a change in purchases are not enough to choose an option. To see how hiding affects category browsing, track detail visits and exits in the hidden arm through the whole test and report them.
- This result reflects only this category and the stock situation during the test, so do not carry it straight to categories with a different out-of-stock share. Keep the position of grayed-out items and the sorting rule fixed throughout, or you cannot tell whether the difference came from the display or the order.
- If stock levels or the out-of-stock share are unbalanced across arms, do not interpret the result; first check caching, assignment and whether traffic split between the arms as planned. If the split holds, enter each arm's visitors and purchases in the [A/B test significance calculator](https://alidemirbas.com.tr/en/calculators/ab-test) to see whether the gap is beyond chance. If the result stays inconclusive, extend the test long enough to cover different stock periods.

## Frequently Asked Questions

### Can results be interpreted when stock appears different between arms?

The arms share inventory. Investigate caching and assignment if availability differs. Faster stock depletion caused by the variant can affect both arms, creating interference that must be noted.

### What risk comes from keeping greyed-out products in the list?

A list dominated by unavailable items can frustrate visitors. Do not imply they can be purchased. Use category purchase conversion as the primary outcome and monitor exits and available-product discovery.

### Should a stock-notification flow be added during this test?

No. This comparison changes listing visibility. If notifications already exist, preserve their behavior in both arms. Adding a new notification mechanism would expand the treatment.