The Best Shopify Back-in-Stock Apps: An Honest Comparison (2026)

When a product sells out, the shopper who wanted it usually just leaves. A back-in-stock app adds a "notify me when it's back" button so you can capture that shopper and email them the moment you restock. There are several good options on the Shopify App Store, and this guide compares them plainly, including where Restocker is not the best pick.

What they all do (the baseline)

Every credible back-in-stock app does the same core job: show a "notify me" button on sold-out products, collect the shopper's email, and send an automatic alert with a buy link when stock returns. So the real question is not "does it send alerts," it is everything around that: the channels, the pricing model, whether it does anything else, and how it treats your data.

The main options

• Swym Back in Stock is an established, feature-rich option, alerts across email and SMS, and part of a broader wishlist and re-marketing suite. A strong pick if you want a full suite and SMS at scale.
• Back in Stock (by Appikon) and Notify Me! are popular, well-reviewed apps that add email and SMS restock alerts, with Notify Me! also combining preorder flows and discounts.
• STOQ is a newer, focused restock-alerts app that leans on email and SMS delivery.
• Prediko is really an inventory-forecasting and planning suite that happens to include restock alerts. If your main problem is predicting and preventing stockouts, not just notifying, it is a different and heavier tool aimed at that.

These are all reasonable, and several have thousands of reviews. Check each one's current pricing, channels, and reviews on the App Store, since those change. The important thing is to match the tool to your actual problem.

Where Restocker is different

Restocker (full name "Restocker: Preorder & Back in Stock") is built around a few deliberate choices, aimed at merchants who were burned by the pricing or trust gaps in bigger tools:

• Flat, predictable pricing. Free, $9, and $19 tiers with no percentage fees and no per-email metering, so your cost does not climb exactly as the feature starts working.
• A permanent delivery log. Every alert is recorded, queued, sent, delivered, so you can prove a shopper was emailed instead of hoping. Restock alerts are only worth anything if they actually arrive.
• Native pre-orders too. It also sells pre-orders via Shopify's native selling plans, so you can take orders on out-of-stock items safely, not just collect emails.
• No theme code injection and free data export. It installs as a theme app extension and uninstalls cleanly, and your waitlist is yours to export by CSV at any time.

When Restocker is not the right pick

Be honest about your needs. If SMS alerts at high volume are essential to you, or you want back-in-stock bundled into a full wishlist and re-marketing suite, an established app like Swym or Appikon's Back in Stock will serve you better today, they have deeper channel support and far more reviews. If your real problem is forecasting demand and reordering stock, Prediko is aimed at that and a notification app is not. Restocker is the better fit when you specifically want flat pricing, provable delivery, native pre-orders, and a clean, no-code install, without paying a percentage or a per-email fee.

How to choose, in one minute

• Need SMS at scale or a full marketing suite? Look at Swym or Back in Stock (Appikon).
• Need to forecast and prevent stockouts, not just notify? Look at Prediko.
• Want simple flat pricing, provable email delivery, and native pre-orders with a clean install? That is what Restocker was built for.