# Never lose a sale to out-of-stock again

Let customers subscribe to back-in-stock alerts on WhatsApp. When the product returns, Kanal sends an instant notification that drives immediate purchases.

Source: https://getkanal.com/back-in-stock  
Last updated: 2026-10-12

## Out-of-stock means lost customers

When a product is out of stock, most visitors leave and never come back. Email back-in-stock alerts have low open rates and often arrive too late, the product sells out again before customers see it.

## Instant alerts on the fastest channel

WhatsApp back-in-stock notifications are read within minutes, not hours. Kanal captures customer interest with a simple opt-in and sends instant alerts when inventory is restocked, driving impulse purchases before stock runs out again.

### One-click opt-in

Customers subscribe to restock alerts with a single tap. No email forms or account creation needed.

### Instant notifications

Automatic WhatsApp alerts the moment inventory is restocked. Beat email by hours.

### Product images & links

Include product photos and direct buy links in the notification for frictionless purchasing.

### Demand insights

Track which products have the most waitlist subscribers to inform your restocking decisions.

- **96%** Open rate
- **30%** Conversion rate
- **<3min** Time to purchase

## Go further

- [Best Shopify back in stock apps, compared](https://getkanal.com/best-shopify-apps/best-shopify-back-in-stock-apps)

## Frequently asked questions

### How do back-in-stock WhatsApp alerts work?

When a product is out of stock on your Shopify store, customers can opt-in to receive a WhatsApp notification when it's back. Kanal monitors your inventory and automatically sends an alert with a direct purchase link the moment stock is available.

### How do customers subscribe to alerts?

Customers can subscribe via a WhatsApp button on your product page, through a QR code, or by messaging your WhatsApp number. The opt-in process is instant and doesn't require email or account creation.

### What conversion rates can I expect?

Back-in-stock WhatsApp alerts typically convert at 25-35%, significantly higher than email alerts (~5-10%). The immediacy of WhatsApp means customers act quickly before stock runs out again.

### Can I see which products have the most demand?

Yes, Kanal's dashboard shows you how many customers are waiting for each out-of-stock product. Use this data to prioritize restocking and plan inventory better.