If your store has never sold out of anything, you don’t need any of these yet. The reason to install a back-in-stock app is a sold-out product that keeps pulling traffic: a product page that was converting last month, is converting zero this month, and will convert again the moment the next shipment lands. That’s a specific, countable job, and the apps below are the ones built for it.
Who this is for
This guide is for Shopify DTC owners running fewer than 30 people. The founder-led store that’s figuring out whether restock alerts are worth paying for, and the small-team store that already knows they’re and wants to pay the right amount for the right features. If you have more than a handful of SKUs that sell out and come back, the question stops being “should I install something” and becomes “which of these.”
If a product sells out and never comes back, a back-in-stock app can’t help you; a pre-order and launch app is a different tool for a different job. If you want restock alerts going out over SMS, the dynamics (and the costs) look different, and our take on the two SMS platforms a small Shopify store is usually choosing between is in Postscript vs. Attentive for a small Shopify DTC store’s SMS program.
Our pick: Preorder, Back In Stock ‑ STOQ
STOQ by Artos Software is where we’d send most small DTC owners. The free plan is the first reason. Most “free” plans in this category are stripped trials with 10 emails and nothing else; STOQ’s $0 forever tier lists 10 preorders a month, 30 back-in-stock emails a month, unlimited subscriber registrations, automatic restock alerts, 24/7 chat support, and 0% transaction fees. That’s enough to run a real pilot on a small catalog without paying anything.
The paid tiers are the second reason. Lite is $10/month for 100 preorders and 1,000 email/SMS alerts, Pro is $29/month for 400 preorders and 3,000 alerts, and Unlimited is $69/month with no preorder cap and no per-preorder overage. The pricing climbs with usage, not with features; all paid plans “unlock everything,” which matters if you’re one person and don’t want to re-shop apps every time you need a different feature. SMS is metered at $0.025 per message on every paid tier (including Unlimited), so budget for that on top.
The trade-off: if you only want restock alerts and have no plans to run preorders, you’re paying for the preorder engine either way. In that one case, Kbite at $5/month is a cheaper tool for a narrower job.
Runner-up: Notify! Back in Stock+Wishlist
Notify! is the broadest tool in the category. The paid tiers bundle restock alerts, preorders, a wishlist, and web push, which is the longest feature list in this guide. On the Shopify App Store listing, Kickstart is $9.90/month, Starter is $19.90/month, and Standard is $39.90/month, with per-preorder overages of $0.20 on Kickstart and Starter and $0.15 on Standard. SMS is priced per country.
Two things kept Notify! out of the top slot for most small stores. The free Lite plan is tight (10 restock notifications, 5 preorders, 50 wishlist actions a month), so you can test it but not really run it on a free tier the way you can on STOQ. And if you don’t need the wishlist and you don’t need push notifications, you’re paying for them anyway. For a store that’ll use the wishlist as a retention list and send push alerts to app or web-push subscribers, the broader surface area is worth the price.
Also great: Appikon ‑ Back In Stock
Appikon is the longest-running name on this list and still earns its 4.8 across 1,456 reviews on the current Shopify App Store listing. The Starter plan at $19.99/month includes 300 emails, Mailchimp and Klaviyo integration, custom theme support, multiple languages, and template customization; Pro at $29.99/month raises the cap to 1,000 emails and adds a collection-page widget; Premium at $49.99/month covers 3,000 emails and adds countdown timers.
Two reasons we didn’t rank it higher. The free tier is only 10 emails a month, which is a trial rather than a usable plan. And SMS is billed on a wide “$0.05 to $0.40 per message based on the number of characters” range that’s harder to budget than STOQ’s or Kbite’s flat per-message rates. If you already use Klaviyo or Mailchimp and just need a reliable restock engine behind them, Appikon is a defensible pick.
Budget pick: Back In Stock, Notify Me: Kbite
Kbite (listed as “Back In Stock, Notify Me: Kbite” by DEVSQUAT SOLUTIONS) is the cheapest credible paid plan in the category. Basic is $5/month for 500 email notifications, mailing-list sync, multi-language, multi-location, and no branding. Starter is $9/month for 2,500 notifications. Pro is $19/month for 5,000 notifications and custom integrations. The free plan collects unlimited subscribers and sends 30 emails a month. The subscriber cap is often where cheap plans quietly cripple themselves, and Kbite doesn’t do that.
Kbite does one thing: back-in-stock alerts (and price-drop alerts on the same signup). It doesn’t do preorders. Native Klaviyo and Omnisend integration isn’t on the entry tiers. The listing is Built for Shopify at 5.0 stars across 4,353 reviews, which is a strong signal that the “set it and forget it” story is real. If your plan is to install a restock app, confirm it recovers revenue, and only then decide whether to pay more, Kbite’s $5/month tier is the honest starting point.
What about Swym
Swym Back in Stock Alerts is a legitimate app that we didn’t rank for a small DTC store. Its Shopify App Store listing shows no free plan, a 30-day trial, and three tiers: Starter at $19.99/month (up to 1,000 alert requests), Pro at $59.99/month (10,000), and Premium at $99.99/month (25,000, with multi-location support and a REST API). Those plans make sense for a brand running multiple locations or wiring alerts into a wider marketing stack. For a founder-led store that’s still proving the ROI, the cheaper tiers on STOQ, Kbite, and Notify! let you test the thesis first.
How to choose between them
The decision tree is short.
If you also sell preorders (or ever will), STOQ at $0, then $10, then $69 covers both jobs in one app. If you want restock alerts, a wishlist, preorders, and push in one tool and don’t mind paying $9.90–$39.90/month, Notify! has the broadest feature list. If you already run Klaviyo or Mailchimp and just want a reliable restock engine behind them, Appikon at $19.99/month is a defensible pick. And if you only want email alerts and want to pay as little as possible until you’ve proven the revenue, Kbite’s $5/month Basic plan is the cheapest honest answer.
A restock app is one of the small DTC apps that most clearly pays for itself, in the same category as a subscription management app once you have repeat buyers. Pick one, give it a quarter on the smallest tier that fits, and let the recovered-revenue report decide the rest.
