A customer finds the product they want, clicks through — and sees “Sold Out.” Most of them leave and never come back. In fact, research from Shopify partners consistently shows that out-of-stock situations can cause stores to lose up to 40% of the revenue those products could have generated. However, the well-configured back in stock Shopify apps can automatically re-capture that demand the moment your inventory is replenished. In this guide, we compare the top back in stock Shopify apps so you can start recovering lost sales today.
What is a back in stock app for Shopify?
A Shopify back in stock app is a tool that lets shoppers subscribe to receive an automatic notification when a sold-out product becomes available again. Instead of losing that customer forever, you capture their intent and re-engage them at precisely the right moment — when the item they wanted is ready to buy.
Here is how the basic flow works:
- A visitor lands on a sold-out product page in your Shopify store.
- A widget (usually a button or an inline form) prompts them to enter their email or phone number to get notified.
- When you restock the product — either manually or via an inventory sync — the app automatically sends an alert to all subscribers.
- Subscribers click through and complete their purchase.
Depending on the app you choose, the back in stock notification Shopify can be delivered via email, SMS, web push notification, or even WhatsApp. The widget itself is fully embeddable on your product page and can be styled to match your brand.
Why your Shopify store needs a back in stock app
Recover revenue that would otherwise be permanently lost
Visitors who see a “Sold Out” label and find a subscribe option are expressing strong purchase intent — they already want the product. Compare that to cold traffic from an ad campaign, where the visitor is still being persuaded. When a Shopify app back in stock alert lands in their inbox at exactly the right moment, conversion rates are significantly higher than typical marketing emails.
Build a high-intent email and SMS list automatically
Every subscriber who signs up for a restock alert is essentially raising their hand and saying, “I want this product.” Over time, this creates a segmented list of highly engaged customers that you can also use for related marketing campaigns — without paying extra for lead generation.
Reduce bounce rate on product pages
Without a restock widget, a sold-out product page is a dead end. A simple subscription form gives visitors a reason to stay connected with your store rather than heading straight to a competitor. This reduces your effective bounce rate and keeps your brand top-of-mind.
Top 5 back in stock Shopify apps
1. Stock by Artos Software
Best for: Shopify stores that want a flexible all-in-one solution for back-in-stock alerts, pre-orders, and waitlist management — without complicated setup.
Stock is consistently one of the highest-rated back in stock apps on the Shopify App Store. Beyond simple restock notifications, it combines preorder management, waitlists, partial payments, low-stock alerts, and multi-channel notifications into a single app. Merchants can automatically send back-in-stock alerts via email or SMS, customise the “Notify Me” widget to match their storefront. The app also supports multiple languages, Shopify Markets, and multi-location inventory.
Pricing: Free plan available. Paid plans from $10/month
Pros
- Combines back-in-stock alerts, preorders, and waitlists in one app
- Highly customisable “Notify Me” widgets
- Supports email, SMS, and multiple languages
- Strong Shopify + Klaviyo integration
- 24/7 customer support with fast response times
- Works with multi-location inventory and Shopify Markets
Cons
- Free plan limited to 30 emails/month
- SMS notifications cost extra beyond monthly plans
2. Notify Me!
Best for: Growing or mid-size Shopify stores that want a single app to handle restock alerts, pre-orders, and wishlist — with the most powerful feature set available.
Notify! is one of the most feature-rich and best-reviewed back in stock apps on the entire Shopify App Store. Beyond restock alerts, it bundles pre-order functionality, wishlist support, and a low-stock “Only X Remaining” FOMO counter into a single app. Alerts can be sent via email, SMS, and web push. The widget is fully customisable and works on product, collection, and home pages. Multi-language, multi-location, and Shopify POS are all supported. The team offers dedicated support by chat, phone, and email — a rarity in this category.
Pricing: Free plan available. Paid plans from $9.90/month
Pros
- Most complete feature set: restock + preorder + wishlist + FOMO
- Dedicated human support via chat, phone, and email
- Works on product, collection, and home pages
- Strong Klaviyo integration
Cons
- Free plan limited to 5 pre-orders; notifications volume capped on lower plans
- SMS charged separately per message ($0.06+ depending on country)
- Can feel feature-heavy for stores that only need basic restock emails
3. PreOrder Globo | Back in Stock
Best for: Stores already invested in a marketing platform (especially Klaviyo, Hubspot, or ActiveCampaign) that need the smoothest possible pre-order + back in stock integration at a low price point
PreOrder Globo is one of the most established apps, having been live on the Shopify App Store since 2017. It combines a solid back in stock notification system with a full-featured pre-order engine. When a product goes out of stock, the app can automatically switch the button from “Add to Cart” to “Pre-Order,” and then notify subscribed customers the moment it restocks. The app integrates with a remarkably broad set of marketing platforms — including Klaviyo, Mailchimp, Hubspot, ActiveCampaign, Omnisend, Sendinblue, and Weglot — making it one of the most flexible options for stores with existing marketing stacks.
Pricing: Free plan available. Paid plans from $9.90/month
Pros
- Widest marketing platform integrations of any app reviewed
- Seamless “out of stock → pre-order” button switch
- Very affordable Pro plan ($19.90/month for unlimited preorders)
- Responsive support team
Cons
- Free plan limited to 20 preorders and 100 restock emails
- No SMS or push notifications — email-only for restock alerts
- No wishlist feature
4. Kbite Back In Stock
Best for: Stores of any size that want the best-rated, most affordable back in stock notification app — especially those who also want price drop alerts to re-engage price-sensitive shoppers.
Kbite is the highest-rated back in stock Shopify app currently available. While newer than some competitors, it has built an extraordinary reputation through consistently excellent support and a focused, well-executed feature set. What sets Kbite apart is its uniquely generous free plan (unlimited subscribers, automatic email and SMS alerts, unlimited sign-up forms) and its additional price drop alert feature — notifying customers not just when a product restocks, but also when its price falls.
Pricing: Free plan available. Paid plans from $5/month
Pros
- Most generous free plan — unlimited subscribers from day one
- Unique price drop alerts alongside restock notifications
- Very affordable paid plans starting at just $5/month
- Exceptional support consistently praised in reviews
Cons
- No pre-order functionality — purely a notification/alerts tool
- Free plan capped at 30 emails/month (unlimited subscribers but limited sends)
- No Klaviyo or Mailchimp native integration (custom integrations on Pro plan)
- Interface language is English only
5. Essent Preorder Back in Stock
Best for: International stores or B2B merchants who need the most flexible pre-order payment options and the broadest language support, alongside solid back in stock notifications.
Essent is built specifically for merchants who need both a powerful pre-order system and a robust back in stock notification workflow in a single, well-designed app. What distinguishes Essent is its payment flexibility: it supports full payment, partial payment, deposits, deferred payment, split payments, and payment schedules for pre-orders — more options than any competitor reviewed here. Restock notifications support 24 languages, making it an outstanding choice for international stores. Human support is available 24/7 on all plans, including the free tier.
Pricing: Free plan available. Paid plans from $25/month
Pros
- Most payment flexibility for pre-orders of any app reviewed
- 24 languages — strongest multilingual support on this list
- 24/7 human support including on free plan
- Generous free plan: 300 back in stock notifications and 10 preorders/month
Cons
- No SMS notifications — email only for restock alerts
- No price drop alerts
- Professional plan ($59/month) is the most expensive on this list for unlimited features
Conclusion
Out-of-stock situations are inevitable in ecommerce — but the revenue loss that follows is not.
The properly configured back in stock Shopify apps turn a frustrating dead end into an automated recovery machine: capturing high-intent subscribers, notifying them the moment inventory is replenished, and converting them at rates that outperform nearly every other marketing channel.
Start with the free plan of your preferred app, test it with a best-selling sold-out product, and review your analytics after the first restock cycle. In most cases, the recovered revenue will make the next step — upgrading to a paid plan — an obvious decision.
