Built for Shopify
The back-in-stock app that turns sold out into your next sale.
Collect signups when products run out, alert everyone the moment you restock, and see the sale each alert earned.
Free plan, no credit card. Live in 5 minutes.
Your sold-out products are still earning. For someone else.
Customers who can't buy from you today buy from your competitor tomorrow. Slingshot brings them back the moment you restock.
The moment you lose them
Sold out is where the sale ends.
They wanted it. It was gone. So they walk, and buy it somewhere else. Slingshot brings them back the moment you restock.
Reach them where they actually open it.
Email. SMS. Widget on your store. Pick one, pick all three.
Eight templates: three free (Clean, Minimal, Streetwear) plus five premium industry designs (Fashion, Beauty, Jewelry, Supplements, Home). Custom-from domain on Scale with DKIM. Business address auto-injected for CAN-SPAM and GDPR.
Flex SMS
SMS alerts are coming soon: pay-as-you-go, US/CA, with spend caps so a viral product can't blow your budget.
On-site signup widget
An embeddable widget that appears the moment a product is out of stock. Style it to match your theme's fonts, colors, and buttons so it looks native, not bolted on. One click to subscribe, no code required.
Not just alerts. The tools to run them.
See exactly which alerts earned which sales, run campaigns, and keep every message on-brand, all from your Shopify admin.
Every alert, tied to the sale it earned.
Most tools tell you an email was sent. Slingshot tells you it made $127. Each back-in-stock alert is linked to the order it drove, across email, SMS, and the widget, so you can see recovered revenue, not just open rates.
Campaigns
Turn a restock into a moment. Schedule and segment broadcasts to everyone waiting on a product, and let the demand data guide what you reorder.
Editable email templates
Eight on-brand starting points, fully editable. Match your fonts, colors, and voice so every alert looks like it came from you, not from an app.
Back-in-stock alerts are the highest-ROI email a Shopify store can send.
Industry benchmarks from across email and SMS back-in-stock programs.
- 8 to 12%
- Typical recovery rate when alerts go out within 24 hours of restock.
- Industry benchmark across email and SMS
- 70%+
- Average open rate on back-in-stock emails, among the highest of any transactional email type.
- Across major email service providers
- 5 minutes
- Average time to install Slingshot and start collecting your first signups.
- Slingshot internal data
What are your stockouts costing you?
Plug in your numbers. See what you're losing, and what Slingshot can bring back.
Your typical AOV in USD
Distinct out-of-stock events across all variants
How many shoppers want each restocked item, on average
Industry benchmark is 8-12%
$2,250
Estimate only. Recovery rate depends on your category, audience, and how fast you restock.
Install at 2pm. Collecting signups by 2:05.
Install, customize, ship. No code required.
- 1
Connect Shopify
Install from the App Store. We sync your products and inventory automatically.
2 mins - 2
Customize alerts
Pick a template, match your brand colors and voice. Add SMS if you want.
5 mins - 3
Get the sale
The moment a product restocks, we notify the customers waiting for it. You see which alerts earned which sale.
Always-on
Simple, transparent pricing.
Three plans. No contracts. SMS only when you turn it on.
Free
Try it on your first 50 alerts a month.
- 50 notifications/month
- 1 customer locale
- Email notifications
- 3 free templates (Clean, Minimal, Streetwear)
- Basic revenue tracking
Growth
For stores doing 100-1,000 orders a month.
- 1,000 notifications/month
- 3 customer locales
- Email + on-site widget
- Custom branding & templates
- Basic revenue tracking
- Email overage at $0.01 (capped at $30/mo)
Scale
For high-volume stores with 1,000+ orders per month.
- 5,000 notifications/month
- Unlimited customer locales
- Email + Flex SMS + on-site widget
- Custom-from email domain (DKIM)
- Advanced revenue tracking
- Flex SMS (coming soon)
Why we're different
Klaviyo sells a marketing suite. We sell a back-in-stock app. That's the whole pitch.
Thomas, Slingshot
One thing, done well.
Klaviyo gives you a marketing suite. Slingshot gives you a back-in-stock app. And tells you which alerts earned which sale.
| Feature | Slingshot | Klaviyo Email |
|---|---|---|
| Back-in-stock alerts | Yes | gated to Email plan |
| Revenue attribution per alert | Built-in | Manual reporting |
| Email + SMS + on-site widget | Yes | bundled with full CRM |
| Custom-from email domain (DKIM) | Scale plan | Yes |
| 8 templates included | Yes | Yes |
| Pay only for back-in-stock | Yes | Bundled with marketing |
| Price at comparable volume | $49/mo | $200+/mo |
Compared at Klaviyo's Email tier with ~10k contacts, which matches Slingshot Scale at 5,000 alerts. Slingshot plans start free, then $19/mo. Flex SMS is coming soon.
Frequently asked questions
If something's missing, write to thomas@heyslingshot.com.
Friends running Shopify stores were paying $300 a month to send one email. So I built the smaller, sharper version.
Stop losing sold-out shoppers to the next tab.
Your first 50 alerts a month are free. The next stockout pays for the rest.