How-to's · Shopify · 3 min read
How to Install Back-in-Stock Alerts on Shopify
Short answer
Shopify doesn't send back-in-stock alerts natively, so install a restock notification app (or use Klaviyo's back-in-stock feature), turn on its app embed or block in the theme editor so a 'Notify me' button replaces Add to cart on sold-out variants, and customize the email or SMS that fires when inventory returns.
When a product sells out, most stores show a greyed-out button and lose the visitor. A back-in-stock alert turns that visitor into a lead: they leave an email or phone number and you notify them when inventory returns. Restock emails tend to convert well because the person already wanted the product.
Option 1: A dedicated restock app
Search the Shopify App Store for "back in stock." Popular apps offer:
- A "Notify me when available" button on sold-out products and variants
- Email, SMS and sometimes push notifications
- Automatic sending when inventory goes above zero
- Reports showing demand for each product
Pick one with recent positive reviews, theme compatibility and pricing that fits your volume. Many have free tiers for small stores.
Installing it
- Install the app and approve permissions.
- In Online Store > Themes > Customize, open Theme settings > App embeds and turn on the app's embed. Some apps use a product page block instead.
- Open the app's settings and customize the button text and signup form.
- Edit the notification email: subject, product image, button and brand colors.
- Test it: set a test product to zero inventory, sign up, then restock it.
Option 2: Klaviyo back-in-stock
If you already use Klaviyo, its back-in-stock feature collects subscribers for sold-out items and triggers a flow when inventory updates. Setup involves adding Klaviyo's back-in-stock code or block to your theme and building a flow using the back-in-stock trigger. The advantage is everything stays in one email platform with your other data. Our Klaviyo vs Mailchimp comparison covers why many Shopify stores pick Klaviyo.
Make sure Shopify tracks inventory
Alerts rely on inventory changes. In each product, confirm:
- Inventory tracked is on.
- Continue selling when out of stock is off for products where you want the alert to show. If it's on, the product never looks sold out. More on that setting in Shopify continue selling when out of stock.
Writing restock emails that sell
- Subject line: Plain and specific works. "The [product] is back in your size" beats clever wordplay.
- Show the exact variant the person signed up for.
- Create honest urgency: if stock is limited, say so. Don't invent scarcity.
- One button straight to the product page, ideally with the variant pre-selected.
- Send promptly. Delays mean other customers grab the stock first.
If demand is high, consider notifying people in batches so the first group doesn't hit a sold-out page again.
Use the data
Signup counts are free market research. If 400 people wait for a color you only reorder occasionally, order more. If nobody signs up for a product, maybe don't restock it. Some apps export this data, and you can bring it into your purchasing decisions.
Back-in-stock vs pre-orders
| Back-in-stock alert | Pre-order | |
|---|---|---|
| Captures payment now | No | Yes |
| Needs a firm restock date | No | Yes, ideally |
| Risk | Customer may lose interest | Delays cause refunds and complaints |
| Best for | Unpredictable supply | Known incoming stock, launches |
If you know when stock arrives, pre-orders can capture revenue immediately. See our guide to pre-order apps for Shopify.
Common problems
- Button doesn't appear: The app embed is off or your theme uses a custom product form. Contact the app's support.
- Emails didn't send: Inventory was updated through a channel the app doesn't watch, or the product had "continue selling" on.
- Wrong variant notified: Check the app tracks variants separately.
Back-in-stock alerts are one of the quickest wins in ecommerce. They take an hour to set up and recover sales you'd otherwise never see.
Frequently asked questions
Does Shopify have built-in back-in-stock notifications?
Not as a standard storefront feature. Merchants use apps or an email platform like Klaviyo to collect signups and send restock alerts.
Should I use back-in-stock alerts or pre-orders?
Alerts suit unpredictable restocks. Pre-orders suit cases where you know the restock date and want to capture revenue now.
Do back-in-stock alerts work for variants?
Yes. Good apps track signups per variant, so someone waiting for a medium in blue isn't emailed when the small in red returns.
Sources and further reading
Platform features, prices and policies change. Check the official help pages linked above before you act on a detail that matters to your store.