Low-stock messaging and restock alerts are different conversion tools. One creates urgency before inventory runs out. The other captures demand after inventory is gone.
Use low-stock messaging while shoppers can still buy
Messages such as "Only 3 left" can help shoppers make a decision while the product is still available. The message should be accurate and should not create false scarcity.
Use restock alerts when the product is unavailable
Once a selected variant cannot be purchased, the page needs a different action. A Notify me button captures demand and gives the shopper a reason to return.
Avoid conflicting states
Do not show "Only 3 left" for a variant that is actually unavailable. Product-page logic should follow the selected variant's true inventory state.
Bodanu Back in Stock combines low-stock messaging settings with unavailable-variant notification workflows.