Capture demand

Turn "sold out" into a signup

When products go out of stock, RestockSignal captures buyer intent with a clean, customizable widget — right on the product page.

"Notify Me" widget

An elegant signup form appears automatically when a product or variant is out of stock. Customers enter their email in one click.

Variant-aware

Customers sign up for the specific size, color, or option they want — not just the product. You get precise demand data.

Theme-compatible

Works with any Shopify theme. The widget adapts to your store's design with zero custom code.

Convert demand

Instant alerts the moment stock returns

Shopify fires an inventory webhook when you restock. RestockSignal picks it up and emails waitlisted customers — automatically, in under 60 seconds.

Webhook-driven delivery

No polling. No manual triggers. Inventory webhooks fire the moment stock changes — and we send within 60 seconds.

Deliverability-first

SPF/DKIM-verified sending via Postmark. Your alerts land in the primary inbox, not spam or promotions.

Waitlist confirmation

Customers get instant confirmation when they join a waitlist. Builds trust and reduces "did it work?" anxiety.

Track performance

See what your customers want

Know exactly which products are in demand, how many customers are waiting, and how your restock alerts perform.

Demand dashboard

See waitlist counts by product and variant. Identify high-demand items and prioritize restocking decisions.

Notification tracking

Track emails sent, customers notified, and unsubscribe rates. Know your alert performance at a glance.

Inventory intelligence

Use waitlist data to inform purchasing decisions. Restock what your customers are actually waiting for.

Built for trust

Designed to feel helpful, not pushy

Every decision we make prioritizes your brand and your customer's experience. Clean messaging, easy opt-out, and no dark patterns.

One-click unsubscribe

Built-in, compliant unsubscribe flow in every email. Protects your brand and keeps deliverability clean.

Explicit opt-ins only

Customers actively choose to be notified. No pre-checked boxes, no assumed consent, no spam.

Rate-limited sending

Smart rate gates prevent email flooding when high-demand products restock. Controlled, reliable delivery.

Setup

Live in 5 minutes

Install the Shopify app, and the widget is automatically added to your product pages. We handle the rest.

5-minute install

Add the app, enable the widget block, and you're live. No code changes, no developer needed.

White-glove onboarding

For beta partners, we install and configure everything — then run a test alert to confirm the full flow works.

Reliable infrastructure

Hosted on Fly.io with Supabase Postgres and Postmark email. Built to be fast, reliable, and available.

Let's run a pilot on your store

We'll install, test, and share initial results within a week. Free for 3 months, no card required.

Start your free pilot →