A shopper finds the exact thing they want on your store. They go to buy it. Then they see it. Sold out.
Most of them leave. And most never come back.
That is real money walking out the door. A back in stock app stops it. It lets shoppers ask to be told the moment an item returns. The best apps go one step further. They also let people buy right now with a preorder, so you keep the sale instead of hoping the customer comes back.
Quick answer: for most stores, pick an app that does both preorders and back in stock alerts. Our top free pick is Oxify Preorder & Back in Stock Preorder. The most proven paid option is STOQ. The full list, honest notes, and setup steps are below.
Best back in stock apps at a glance
| App | Rating (reviews) | Price | Preorder? | Best for |
|---|---|---|---|---|
| Oxify Preorder & Back in Stock | New | Free | Yes | Best free app that does both jobs |
| STOQ | 5.0 (3,270) | Free plan, then $10+ | Yes | Most proven all-rounder |
| Notify! (Appikon) | 4.9 (3,253) | Free plan, then paid | Yes | Alerts plus a wishlist |
| Timesact | 4.9 (1,883) | Free plan, then paid | Yes | Product drops and launches |
| Essent Preorder | 5.0 (1,148) | Free plan, then paid | Yes | Simple preorder and waitlist |
| Swym Back in Stock | 4.7 (436) | From $19.99/mo | Yes | Big stores that need deep integrations |
| Klaviyo | Email platform | Free to start | No | Stores already using Klaviyo |
Ratings and review counts come from the Shopify App Store and were checked while writing this guide. App Store numbers change over time, so treat them as a snapshot, not a fixed score.
How we picked these apps
We did not just copy other lists. For each app we looked at:
- The current Shopify App Store rating and review count
- Real merchant reviews, including the complaints, not just the praise
- Pricing, including free plans and hidden limits
- Whether the app can both send restock alerts and take preorders
- How easy it is to set up with no code
That is why you will see honest “watch out” notes below, even for popular apps.
Why a “Sold Out” button quietly drains your sales
When a product runs out, a lot happens that you never see:
- The shopper leaves your store.
- They forget the product name.
- They find the same item on another site.
- You lose the sale, and maybe the customer for good.
A plain “Sold Out” button is a dead end. It tells people to go away. A back in stock button turns that dead end into a door. Instead of leaving, the shopper leaves their email and waits for you. When you restock, they get a message and come back to buy.
That one small change can bring back sales you thought were gone. Out of stock is only one way stores lose sales. For the rest, see our guide to the best Shopify apps to reduce cart abandonment.
Back in stock vs preorder: the difference that matters
Here is something most “best apps” lists skip. There are really two ways to save a sale when stock is low or zero.
Back in stock alerts. The shopper joins a waitlist. You email or text them when the item returns. This is great, but there is a catch. You still have to wait for them to come back and buy. Some will. Some will forget.
Preorders. The shopper buys the item now, even though it is out of stock. You take the payment, or just a small deposit, and you ship it when it arrives. The sale is done. No waiting. No “maybe.” Preorders usually need an app, since Shopify has no full preorder feature built in.
Here is a simple example. Say you sell candles, and your best scent sells out. With a preorder, a superfan buys it today and you ship next week. With a back in stock alert, a casual shopper leaves their email and you win them back on restock day. Use both, and you catch both kinds of buyer.
This is a big reason the top apps in 2026 now bundle preorders and restock alerts together. When you shop this list, look for apps that do both.
The 15 best back in stock apps for Shopify
1. Oxify Preorder & Back in Stock (best free app that does both)
Oxify Preorder & Back in Stock does the two things that matter most, and it does them for free.
You can add a preorder button to any product that is out of stock, low on stock, or coming soon. Shoppers can buy right away, pay a deposit, or split the cost into parts. When something is fully sold out, they can join a waitlist and get an automatic email the moment it is back.
- Preorder button and badge for out of stock or upcoming items
- Take a deposit, partial payment, or split payment at checkout
- Automatic back in stock emails for your waitlist
- Add a discount to reward early buyers
- Works inside your current theme with no code, and works with Shopify POS
Rating: New. It launched in July 2026, so it has no reviews yet.
Best for: Any store that wants preorders and restock alerts in one free app.
Watch out: It is the newest app on this list, so it has the smallest track record.
Price: Free.
Because it covers both jobs in one place, you are not paying for two apps or stitching tools together. If you want a free way to save more sales today, this is the one to start with.
2. STOQ (most proven all-rounder)
STOQ is the most reviewed app on this list, with a perfect 5.0 rating across more than 3,200 reviews. That kind of track record is rare.
It adds a “Notify Me” button to sold-out products and sends alerts by email, SMS, or push. It also handles preorders with deposits and partial payments, syncs with Klaviyo and Mailchimp, works with Shopify POS, and supports more than 20 languages. Support is available around the clock.
Rating: 5.0 (3,270 reviews). Built for Shopify.
Best for: Store owners who want a well-known app with a long, proven history.
Watch out: The free plan is small (about 10 preorders and 30 emails per month), and SMS messages cost extra. You will likely need a paid plan as you grow.
Price: Free plan, then $10, $29, or $69 per month.
3. Notify! Back in Stock (Appikon)
Notify! by Appikon blends restock alerts, a wishlist, and preorders into one app, with a 4.9 rating across more than 3,200 reviews. Shoppers can save items they love and get told when those items come back.
It sends email, SMS, and push alerts, shows low-stock counts, gives you demand reports, and sets up on most themes fast.
Rating: 4.9 (3,253 reviews). Built for Shopify.
Best for: Stores that want alerts plus a wishlist to track what people want.
Watch out: A few reviewers have reported alert delays during very large launches, so test it before a big product drop.
Price: Free plan, with paid plans as you scale.
4. Timesact (best for product drops)
Timesact is built for stores that run launches and drops. It has a 4.9 rating across more than 1,800 reviews. It handles “coming soon,” preorders, and back in stock alerts, and it works closely with your inventory, so the message on the page updates on its own as stock changes.
Rating: 4.9 (1,883 reviews). Built for Shopify.
Best for: Owners who plan drops and want the product state to drive the message.
Watch out: It is preorder-first, so back in stock alerts are one part of a bigger toolset.
Price: Free plan, with paid plans as you scale.
5. Essent Preorder Back in Stock
Essent is a clean, well-liked option with a 5.0 rating across more than 1,100 reviews. It focuses on preorders and a simple back in stock waitlist, without a lot of extra clutter.
Rating: 5.0 (1,148 reviews). Built for Shopify.
Best for: Stores that want a simple, solid preorder and waitlist app.
Watch out: It is lighter on marketing extras than bigger apps like STOQ.
Price: Free plan, with paid plans as you scale.
6. Swym Back in Stock Alerts
Swym is a long-time name, live since 2016 and installed on more than 20,000 stores, with a 4.7 rating. It sends email and SMS restock alerts, supports preorders, shows AI-powered “you might also like” picks for sold-out items, and links up with many marketing tools like Klaviyo, Mailchimp, and Postscript.
Rating: 4.7 (436 reviews).
Best for: Bigger stores that already use several marketing tools and want deep links between them.
Watch out: There is no free plan anymore. Plans start at $19.99 per month, and one recent reviewer said the entry plan “costs almost as much as Shopify itself.” The app is also English-only.
Price: From $19.99 per month, with a 30-day free trial.
7. Klaviyo (if you already use it)
Klaviyo is a full email and SMS marketing platform, and it has a built-in back in stock feature. If you already send your newsletters and flows through Klaviyo, you can turn on restock alerts without adding a separate app.
Best for: Stores that already run their email marketing on Klaviyo.
Watch out: It does not offer preorders, and it is heavier than a simple alert app. It is priced by the size of your contact list, so it can get costly.
Price: Free to start, then priced by your number of contacts.
8 more back in stock apps, compared
The seven above are our top picks, but these apps can fit special needs. Here they are at a glance, then in detail. Ratings and prices change over time, so check the App Store before you install.
| App | Standout feature | Starting price |
|---|---|---|
| Back In Stock: Customer Alerts | Simple, classic email and SMS alerts | Free plan, then paid |
| Alert Me! Restock Alerts | Tracks the revenue and ROI your alerts bring in | Free plan, then about $9.99/mo |
| Hulk Restock Alerts | Affordable, with unlimited alerts on one plan | Free dev plan, then about $9.90/mo |
| KB Back In Stock | Adds price drop and abandoned cart alerts | Free plan, then about $5/mo |
| PreOrder Globo | Preorders alongside restock alerts | Free plan, then about $9.90/mo |
| PushOwl (Brevo) | Leads with browser push, not just email | Free plan, then about $19/mo |
| Stok Back in Stock Alert | Restock alerts plus price drop alerts | Free plan available |
| Ordersify | Clean, reliable “Email me” alerts | Free plan available |
9. Back In Stock: Customer Alerts (SureSwift Capital)
One of the oldest and most reviewed back in stock apps on Shopify. It puts a “Notify me when available” button on sold-out products and sends an email or text the moment you restock.
- Automatic email and SMS restock alerts
- Five-minute setup with no code, plus a JavaScript API for custom buttons
- Demand analytics to see which products people want most
Best for: Stores that want a simple, proven, alerts-only app.
Watch out: It does not do preorders. Because it has been around a long time, it also carries more low-star reviews than newer apps, and a few merchants feel the paid plans run pricey.
Price: Free plan, with paid plans as you grow.
10. Alert Me! Restock Alerts (Dibble Development)
Alert Me! is built around one idea: proving that your restock alerts make money. It adds sign-up forms to product and collection pages, then tracks the revenue those alerts bring back.
- Revenue and ROI tracking for every restock alert
- Sign-up by variant, so buyers do not wait for every size to sell out
- Customizable buttons and emails to match your brand
Best for: Store owners who want to see the exact revenue their alerts earn.
Watch out: Support replies can be slow, and design options are a bit limited.
Price: Free plan, then about $9.99 per month.
11. Hulk Restock Alerts (HulkApps)
A budget-friendly restock alert app from HulkApps, a long-time Shopify developer. It sends automatic email and SMS alerts and lets you manage your whole inventory from inside the app.
- Automatic email and SMS restock alerts
- Full inventory access from within the app
- One simple paid plan with unlimited alerts
Best for: Stores that want cheap, unlimited alerts without extra frills.
Watch out: Some users report bugs and a dashboard that can feel slow, with support that is not always quick.
Price: Free development plan, then about $9.90 per month.
12. KB Back In Stock
KB packs a lot into a low price. On top of restock alerts, it also sends price drop alerts and abandoned cart reminders, and it builds a waitlist so you can see real demand.
- Email and SMS restock alerts, plus price drop and abandoned cart alerts
- A waitlist that tracks demand for each product
- A very low starting price
Best for: Small stores that run frequent sales and want alerts plus price-drop nudges.
Watch out: Setting up the widget may need help from support, and uninstalling can be fiddly.
Price: Free plan, then about $5 per month.
13. PreOrder Globo
As the name says, PreOrder Globo leans toward preorders, but it also handles back in stock alerts. You can add a preorder button to any product, take partial payments, and add an automatic discount.
- Preorder button with partial payments and automatic discounts
- Back in stock email, SMS, and pop-up alerts
- Set preorder start and end times, plus a countdown
Best for: Stores running presales that also want restock alerts in the same app.
Watch out: Countdown options are limited, and a few users hit small bumps when switching products in and out of preorder.
Price: Free plan, then about $9.90 per month.
14. PushOwl (now part of Brevo)
PushOwl takes a different path. Instead of leading with email, it leads with browser push, so a shopper only has to click “Allow,” with no email or phone needed. It carries a 4.8 rating across well over a thousand reviews.
- Web push, email, and SMS in one app, with unlimited subscribers
- Back in stock reminders and price drop alerts
- Fast setup and strong abandoned cart recovery
Best for: Stores that want to reach anonymous visitors who never share an email.
Watch out: Push works best with real traffic, so very small stores get less from it, and the many features can feel like a lot at first.
Price: Free plan with limited monthly sends, then about $19 per month.
15. Stok Back in Stock Alert
Stok focuses on getting the right message out fast. It sends back in stock alerts by email and SMS, and it also sends price drop alerts, which many alert apps skip.
- Email and SMS restock alerts
- Price drop alerts for items on sale
- A clean button that sits nicely under a “Sold Out” button
Best for: Stores that want restock and price drop alerts in one simple tool.
Watch out: It is alerts-focused, so it is not the pick if you need full preorders. (This is a different app from Appikon’s Notify! in our top 7.)
Price: Free plan, with paid plans available.
16. Ordersify
Ordersify keeps things clean and reliable. Shoppers join with a simple “Email me when available” button, and the app sends automatic or manual restock alerts by email and SMS.
- Automatic or manual email and SMS restock alerts
- Works with most themes and syncs with your inventory
- Simple, no-fuss setup
Best for: Stores that just want dependable restock alerts without a learning curve.
Watch out: It is focused on alerts, so preorder features are limited.
Price: Free plan, with paid plans available.
If you are also running out of stock too often in the first place, an inventory forecasting tool like Prediko can warn you before items hit zero, so fewer products need a waitlist at all.
Email vs SMS vs push: which alert works best?
Most apps let you send alerts in more than one way. Here is a simple guide:
- Email is free or cheap, works everywhere, and is the safe default. Downside: inboxes are crowded, so some people miss it.
- SMS (text) gets opened fast and works great for hot items. Downside: it usually costs extra per message, so watch your bill.
- Push notifications pop up on the phone or browser with no email needed. Downside: the shopper has to opt in first, so fewer people get them.
Simple rule: turn on email for everyone. Add SMS for your best sellers, where a fast alert is worth the small cost.
If you already send a lot of marketing email, a dedicated tool can handle restock emails too. See our roundup of the best Shopify email marketing apps.
How to write restock alerts that sell
Getting the shopper to sign up is only half the job. The message you send when the item returns is what makes the sale. Keep these tips in mind:
- Send it fast. The best time to reach a shopper is the minute the item is back. A late alert is a missed sale.
- Show the exact product. Put the product name and a photo in the message, so they remember why they wanted it.
- Add a little urgency. A line like “Only a few left” or “Selling fast” pushes people to act now, not later.
- Give a small reason to buy today. Free shipping or a small discount for the next day can tip a maybe into a yes.
- Let them choose email or text. Some people never open email. Let them pick how they hear from you.
- Add one clear button. Link straight to the product, so buying takes one tap.
- Keep it short. One product, one message, one button. Do not bury the point.
Here is the difference in practice. A weak alert says: “Back in stock. The item you wanted is available again.” It is easy to ignore. A strong alert says: “Your size is back, and it is selling fast. Only a few left of [product name].” Then it shows the product photo and one clear “Buy now” button. Same news, but the second one gets the click.
How to choose the right app for your store
You do not need the app with the longest feature list. You need the one that fits how you sell. Ask yourself:
- Do I want the sale now, or later? If now, you need preorders, not just alerts.
- Do I run drops or restocks often? If yes, pick an app with reminders and smart automation.
- Do I sell in many countries? Look for multiple languages. (Note: Swym is English-only.)
- Do I want to keep costs low? Start with a free plan like Oxify Preorder & Back in Stock, STOQ, Notify!, Timesact, or Essent.
- Do I want one app or two? An app that does both preorders and alerts saves money and time.
Short answer: if you want free and simple, start with Oxify Preorder & Back in Stock. If you want the most proven app and do not mind paying as you grow, go with STOQ.
How to set up back in stock alerts in 4 steps
You do not need to be a developer. Most apps follow the same simple path:
- Install the app from the Shopify App Store and open it in your admin.
- Turn on the button. Pick “Notify me” for alerts, “Preorder” to sell now, or both.
- Match your brand. Change the button text and colors so it fits your store.
- Write your message. Set a short, friendly email that goes out the moment you restock.
That is it. Once it is live, the app does the work while you focus on running your store.
Get more from every saved sale
A back in stock or preorder sale is a great win. But you can make each one bigger.
When a shopper finally buys the item they waited for, that is the perfect moment to show a matching product or a small “add this too” offer. A slide-out cart with upsells, like Oxify Cart Drawer, can turn one saved sale into a slightly larger order. Pairing preorders with smart cart upsells is a simple way to lift your average order value without paying for more traffic.
Frequently asked questions
What is a back in stock app?
It is a Shopify app that lets shoppers sign up to be told when a sold-out product returns. When you restock, the app sends them an email, text, or push alert so they can come back and buy.
Do back in stock alerts really increase sales?
Yes. Instead of losing a shopper the moment they see “Sold Out,” you save their interest and bring them back when the item returns. Many stores add preorders too, so they catch the sale right away.
What is the difference between a preorder and a back in stock alert?
A preorder lets a shopper buy an out-of-stock item now, and you ship it when it arrives. A back in stock alert only saves their email and tells them later, so they still have to return to buy.
What is the best free back in stock app for Shopify?
Oxify Preorder & Back in Stock is free and covers both preorders and restock alerts. STOQ, Notify!, Timesact, and Essent also offer free plans with limits.
Which back in stock app has the most reviews?
STOQ has the largest review base of the apps here, with a 5.0 rating across more than 3,200 Shopify App Store reviews.
Can I collect a deposit on a preorder?
Yes, with the right app. Oxify Preorder & Back in Stock and STOQ both let shoppers pay a deposit or split the cost, so they can commit without paying the full price upfront.
Do back in stock apps slow down my store?
Good ones do not. Look for the “Built for Shopify” badge, which means the app meets Shopify’s higher bar for speed and design.
Is email or SMS better for restock alerts?
Email is the cheap, safe default. SMS gets opened faster and works well for hot items, but it usually costs extra per message. Many stores use email for everything and add SMS for best sellers.
How much do back in stock apps cost?
Many have a free plan, including Oxify Preorder & Back in Stock, STOQ, Notify!, Timesact, and Essent. Paid plans usually run from about $5 to $100 per month, based on how many alerts or preorders you send.
The bottom line
A “Sold Out” sign should never be the end of the sale. With the right app, it becomes the start of one.
If you want the simplest way to save more sales, pick an app that does both preorders and back in stock alerts. Oxify Preorder & Back in Stock does exactly that, it is free, and you can set it up today with no code.
Turn your sold-out products into your next round of orders.
