Kernvel Back in Stock icon
🧰 Kernvel Free Tools · In development · Coming to the Shopify App Store

Sold out shouldn’t mean sale lost.

When a product sells out, the demand doesn't stop — it just leaves. Kernvel Back in Stock captures it with a one-field email signup, tells shoppers the moment you restock, and shows you exactly which products people are waiting for.

1
Field to capture demand
Availability checks before send
180
Days privacy retention
$0
Free forever

Every sold-out page is a decision point

🚪

Demand walks out silently

A sold-out page with no signup is a dead end — the shopper leaves, buys elsewhere, and you never even know they wanted it.

🧭

Restocking blind

Without a waiting list, restock decisions run on gut feel. With one, you restock the products people are literally lined up for.

Urgency sells the last units

"Only 3 left" moves fence-sitters. The same widget adds honest low-stock urgency from your live inventory — no fake scarcity.

From lost sale to recovered revenue

Best for drops, fast sellers, and inventory-constrained catalogs. Every feature below ships in the free app — there are no paid tiers.

📬

Back-in-stock email alerts

A clean signup on sold-out variants; when inventory returns, delivery is confirmed against your live storefront twice before any email sends — no false alarms.

⏱️

Low-stock urgency badge

"Only {qty} left!" appears automatically when a variant drops to your threshold — driven by real inventory, with the wording and threshold fully yours.

🏆

Most-wanted restock list

Products ranked by how many shoppers are waiting — your restock priority list, exportable to CSV for the buying meeting.

✉️

Emails in your voice

From-name, reply-to, subject, heading, and intro are all customizable with the product name substituted in — and the test-email button shows exactly what shoppers get.

📈

Demand analytics

Daily signups versus notifications sent, live waiting counts, and lifetime totals — the full demand-recovery funnel at a glance.

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Privacy-first by default

Shopper emails exist only until the alert is delivered, unsubscribes are one click and hashed, unfulfilled signups auto-delete after 180 days, and open/click tracking stays off.

Up and running in minutes, not projects

1️⃣

Add the widget

Drop the block on your product template — the low-stock badge and sold-out signup appear automatically from live inventory.

2️⃣

Restock what's wanted

Check the waiting list, restock the top of it, and update inventory like you always do.

3️⃣

The app does the rest

Restocks are detected from inventory events, availability is double-checked, and the alerts go out with automatic retries.

Free means actually free

No plans, no feature gates, no surprise charges. These tools are how we earn trust with merchants — and every one includes a free concierge setup call with our team.

🆓

$0, forever

No subscription, no usage caps, no premium tier hiding the good parts. The app you install is the whole app.

🔍

Transparent by design

Rule-based and deterministic — no AI black boxes. You can always see exactly why the app did what it did.

🔒

Privacy-first

No shopper profiling, aggregate-only counters, minimal Shopify permissions, and data that cleans up after itself.

Before you install

No. One alert per signup, sent only after the item is confirmed purchasable — then the address is deleted from the waiting list. Rate limits and a honeypot keep bots out.

Yes — sender name, reply-to, subject, heading, intro, and accent color, with {product} substitution. Send yourself a test email to preview it exactly.

There is none. The low-stock badge reads your live inventory; if you have 40 in stock and your threshold is 5, nothing shows.

Unlimited signups and alerts, the demand dashboard, analytics, CSV export, and every customization. No plans, no limits.

Want it configured for you?

Every Kernvel Free Tool comes with a free concierge setup — a 15-minute call where our team configures the app for your store. That's the whole pitch: useful tools, set up properly, no invoice.

More Free Tools: Product Feed Audit · Catalog Audit · Shipping Calculator · Gift Wrap · Personalization