Back in stock app that turns sold-out pages into sales
A back in stock app lets shoppers ask to be told when a sold-out item returns. CartAbandon adds a signup to every sold-out variant, alerts people in the order they signed up, and throttles sends so a small restock does not oversell. Each alert goes by the channel the shopper consented to.
A sold-out page should collect demand, not lose it
When a product sells out, the page still gets visits. Without a back in stock signup, those shoppers leave and buy elsewhere. With one, they leave a contact and wait for you. You keep the demand and learn which variants people want most.
A back in stock alert is also one of the most welcome messages a store can send. The shopper asked for it. They know what it is about. And it arrives when they can finally buy.
Shoppers sign up on the exact variant they want
The signup sits on the product page when the selected variant is sold out. If a hoodie is out in medium but in stock in large, only the medium shows the signup. The shopper picks a channel and gives consent.
- Variant level. Size, color and style are tracked separately.
- Channel by consent. Email, SMS, WhatsApp or web push, each with its own consent checkbox.
- Consent record. Source and timestamp are saved per contact and channel.
- Mobile-safe. The signup fits small screens and does not cover the page.
- No CAPTCHA. Shoppers type a contact and tap once.
Alerts go out in signup order, throttled to your stock
A restock of 40 units with 600 people waiting can go wrong fast. If everyone gets an alert at once, hundreds of shoppers reach an empty page again. That is worse than no alert.
CartAbandon handles a restock in steps:
- Detect the restock. The stock level for the variant goes above zero.
- Count the units. It reads how many units came back.
- Notify in order. The first people who signed up are alerted first.
- Throttle the batch. It sends alerts in batches sized to the stock, then waits to see how many sell.
- Keep going or stop. If units remain, the next batch goes out. If the variant sells out again, the remaining signups stay on the list for the next restock.
Quiet hours by the shopper's time zone still apply. A shopper in another time zone gets the alert in the morning, not at night. Frequency caps stop the same person getting several alerts in one day across different items.
Example restock
This is an illustrative example with assumed numbers. A store restocks 30 units of a sold-out sneaker in size 9. There are 210 signups. CartAbandon alerts the first batch in signup order, watches sales, then alerts the next batch while units remain. When the size sells out again, the rest of the list waits for the next restock.
Each alert uses the channel the shopper chose
Back in stock alerts are short and simple. The product, the variant, the price and a link straight to the page.
| Channel | Good for | Consent needed |
|---|---|---|
| Most shoppers, with product photos | Yes, email consent | |
| SMS | Fast-selling items where speed matters | Yes, SMS consent, STOP honored |
| Shoppers who prefer chat | Yes, WhatsApp opt-in and opt-out | |
| Web push | Shoppers on desktop who allowed push | Yes, browser permission |
Read how each channel works on the channels page, or see how texts are handled on the abandoned cart SMS page.
Recovery Brain knows when stock is low
Stock level is one of the signals the Recovery Brain reads for every recovery message, not only for restocks. If a shopper left a cart with an item that has 3 units left, a reminder is useful, and a discount is not needed. If an item is back after selling out, the alert itself is the reason to buy.
That is why back in stock alerts carry no discount by default. You can allow one, within your max discount and minimum margin rules, but most restocks do not need it. Learn more on the Recovery Brain page.
Signup lists show which products to reorder
Every signup is a vote for a variant. The panel shows how many people are waiting for each product and size. That helps you decide what to reorder first and in what quantity. A variant with 400 people waiting is a clear signal. One with 3 is not.
Back in stock alerts start on Growth
Back in stock and price drop alerts are included from Growth at 149 USD per month, or 74 USD per month billed yearly. Growth also adds web push, Recovery Brain per-cart decisions and WhatsApp. Scale and Plus include everything in Growth with higher limits. Prices are flat, with SMS and WhatsApp included within plan limits.
FAQ
Questions about back in stock app
What does a back in stock app do?
It lets shoppers sign up on a sold-out product and sends them an alert when it is available again. CartAbandon does this per variant, by the channel each shopper consented to.
Does CartAbandon work as a back in stock Shopify app?
Yes. It connects to Shopify through an app install, and also works with WooCommerce and Magento. The signup appears on sold-out variants of your product pages.
How do you stop alerts from overselling a small restock?
Alerts go out in signup order and in batches sized to the restocked units. If units run out, the remaining signups stay on the list for the next restock.
Can shoppers get back in stock alerts by text?
Yes, if they give SMS consent at signup. They can reply STOP at any time. WhatsApp and web push work the same way, each with its own consent.
Do back in stock alerts include a discount?
Not by default. The shopper asked to be told, so the alert itself is the reason to buy. You can allow a capped offer within your margin rules.
Find out what sold-out pages cost your store
Enter your store URL and see an estimate that includes back in stock recovery.