
The Klaviyo Flows That Convert on Shopify: 8 Templates Worth Stealing


Here's the reality. If your Shopify Plus store is running Scripts right now discount logic, shipping rules, payment conditions all of it stops working on June 30, 2026.
Not "gets deprecated." Not "might change." Stops. Working.
And it gets worse. Starting April 15, 2026, you can't even edit or publish Scripts anymore. That means if your BOGO deal breaks, your tiered pricing glitches, or your wholesale payment routing goes sideways you're locked out. No fixes. No patches. Nothing.
Shopify extended the original deadline from August 2025 to give merchants more time. That was generous. But most stores treated it as permission to procrastinate. And now we're inside 90 days of the April 15 editing freeze.
The stores that move now will have time to test, iterate, and launch clean. The stores that wait until May? They'll be scrambling during their busiest sales season, shipping broken checkouts and bleeding revenue.
This isn't a drill. This is the migration playbook.
If you've been on Shopify Plus for any length of time, you know Scripts. They're the Ruby-based customization layer that lets you manipulate checkout behavior discounts, shipping options, payment methods without touching your theme code.
Scripts come in three flavors:
For years, this was the power tool of Shopify Plus. And it worked.
So why is Shopify killing it?
Three reasons. First, scripts run on sandboxed Ruby interpreters; they're slow under heavy traffic and degrade during flash sales when you need them most. Second, they're completely isolated from Shopify's modern ecosystem. Scripts can't talk to Flow, can't leverage GraphQL, can't integrate with Checkout Extensibility. They're a walled garden on a platform that's going open. Third, they're a maintenance nightmare for Shopify's engineering team. Every platform upgrade has to work around legacy Script behavior.
Shopify didn't make this decision lightly. They extended the deadline once already. But the direction is clear: Scripts are dead. Functions are the future.
Here's the practical roadmap. Keep it focused, keep it moving.
Go to your Shopify Admin and pull the Scripts Customizations Report. This tool identifies every active Script on your store and tells you which ones have direct Function equivalents.
Not every Script needs a custom Function. There are three paths:
For custom builds, scaffold your project with Shopify CLI. Write your logic in JavaScript or Rust. Functions follow a predictable pattern, they receive input (cart data, customer data), run your logic, and return a result (modified prices, hidden payment methods, etc.).
Shopify lets you run Scripts and Functions in parallel until June 30. Use customer tags to A/B test tagged users get the Function experience, untagged users stay on Scripts. Compare results. When they match, you're ready.
Once your Function is verified, remove the testing logic, activate the Function for all customers, and unpublish the old Script in the Script Editor. Monitor your checkout for 48-72 hours post-switch. Watch conversion rates, average order value, and error logs closely during this window.
Shopify Functions is the solution. Think of it as Scripts 2.0 but faster, more powerful, and built for where Shopify is heading.
Instead of interpreted Ruby running in a sandbox, Functions are compiled WebAssembly (Wasm) binaries that execute natively on Shopify's infrastructure. They run in under 5 milliseconds. Every time. Even during Black Friday traffic spikes.
Here's what Functions can do:
And here's what Functions can do that Scripts never could: reject discount codes with a custom error message at checkout, dynamically set payment terms and deposit requirements for B2B stores, and integrate directly with Shopify Flow for automated logic chains.
Functions are deployed as apps either custom apps for your store or public apps through the Shopify App Store. That means non-technical team members can configure settings from the admin without touching code.
Here's the quick side-by-side. No fluff just what matters for your migration decision.
| Feature | Shopify Scripts | Shopify Functions |
|---|---|---|
| Language | Ruby (Script Editor) | JavaScript, TypeScript, or Rust |
| Runtime | Sandboxed Ruby interpreter | Compiled WebAssembly (Wasm) |
| Speed | Variable, slower under load | Under 5ms, consistent |
| Deployment | Script Editor app in admin | Shopify CLI + custom/public app |
| Scope | Line items, shipping, payments | Discounts, delivery, payments, cart validation, fulfillment |
| Plan | Shopify Plus only | Any plan (public apps) / Plus (custom apps) |
| Ecosystem | Isolated from Flow, APIs | Integrated with Flow, GraphQL, Checkout Extensibility |
| Scalability | Degrades during flash sales | Built for high-traffic events |
| Status | Deprecated dies June 30, 2026 | Active Shopify's future |
The takeaway? Functions aren't just a replacement. They're an upgrade across every dimension that matters, speed, flexibility, ecosystem integration, and future-proofing.
The two biggest mistakes we see are stores that start too late and teams that skip QA on edge cases.
Starting too late is self-explanatory, a May migration for a June 30 deadline is asking for trouble. You need time to audit, build, test, and deploy. And if something breaks in testing? You need time to fix it.
Skipping QA is the silent killer. That BOGO Script you wrote in 2021? It probably has conditions you've forgotten about customer tag checks, minimum cart values, product exclusions. All of that logic needs to be rebuilt in your Function.
Here's a real-world example: imagine your store runs a line item script that gives 20% off all products tagged "summer-sale" when the customer is tagged "VIP." In Functions, you'd rebuild this as a Product Discount Function. The logic is straightforward but if you also have a second Script stacking a free shipping rule for VIP customers over $100, you need to make sure both Functions play nicely together. Scripts and Functions execute in different orders, and a discount that changes your cart total could push a customer below that $100 shipping threshold.
Another common scenario: payment gateway Scripts. Say you hide "Cash on Delivery" for orders over $1,000 or for international addresses. When you migrate this to a Payment Customization Function, you need to test every combination domestic under $1K, domestic over $1K, international, mixed carts. One missed edge case and you're showing COD to customers who shouldn't see it.
Test everything. Especially discount stacking, cart edge cases, and international shipping scenarios.
Look, nobody likes forced migrations. But if we're being real Functions are better than Scripts in almost every way.
The merchants who migrate early aren't just avoiding a deadline, they're getting a faster, more reliable checkout that converts better. That's not a cost. That's an investment.
And consider this: Shopify's entire roadmap is built around Functions and Checkout Extensibility now. Every new feature, every improvement, every capability they ship in 2026 and beyond will be built for this architecture. Scripts won't get any of it. By migrating now, you're not just keeping the lights on, you're positioning your store to take advantage of everything Shopify ships next.
April 15, 2026: No more editing or publishing Scripts. Your existing Scripts keep running, but they're frozen. If something breaks, you can't fix it.
June 30, 2026: All Scripts stop executing. Completely. Every checkout customization powered by Scripts discounts, shipping logic, payment routing goes dark.
Let's make this real. Imagine it's July 1. A customer hits your checkout with a cart full of products. Your BOGO deal? Gone. Your free shipping threshold? Gone. Your "hide COD for orders over $500" rule? Gone. The checkout they see is vanilla Shopify with zero customization.
Now multiply that by every order, every day, until someone manually rebuilds your logic in Functions. That's not a hypothetical. That's what happens if you miss the deadline.
And the April 15 freeze is just as dangerous. If you're still tweaking Scripts in March and something goes wrong after April 15, you're stuck with a broken checkout for 10+ weeks until Scripts are fully shut off anyway.
The window to act is right now.
Here's the practical, no-nonsense migration path. Five steps. Let's go.
Start with Shopify's built-in Scripts Customizations Report. You'll find it in your admin under Settings → Checkout → Customizations Report. It lists every active Script, what it does, and suggests replacement paths.
The mapping is straightforward:
For complex logic that combines multiple Script types, you may need Cart Transform API or Checkout Validation in addition to the primary Function API.
You've got three options for each Script:
A: They stop running. Not 'get deprecated.' Not 'might change.' Stops. Any discount, shipping, or payment logic that lives in Scripts will fail to execute after that date. If you have not migrated to Shopify Functions by then, your store will operate as though those rules never existed.
A: No. The editing freeze is April 15, 2026 two and a half months before the runtime cutoff. From April 15 onward, you cannot create, edit, or publish Scripts. Any bug discovered after that date stays a bug until you migrate to Functions or July 1 erases the problem by erasing the Script.
A: For a typical Plus store with 3-7 active Scripts, 4-6 weeks of engineering time if you start with a clean migration plan. Stores with complex Discount Scripts or payment routing logic should plan 8-12 weeks. The variability is mostly in the testing phase, not the porting phase. Functions have stricter input/output contracts than Scripts and the test plan matters more than the code.
A: Functions are included in Shopify Plus and don't have a usage-based fee. The cost is engineering time to migrate. Some merchants worry Functions will incur per-execution charges; Shopify has consistently confirmed that is not the model.
A: Only until June 30, 2026. Today you can run both side-by-side. After June 30, only Functions execute. Most merchants use this overlap window to migrate one Script at a time, validate, and decommission which is exactly the recommended migration order.
A: Almost every Script logic has a Functions equivalent. The cases that genuinely don't translate one-to-one are very rare and usually involve writing custom logic that Shopify designed Functions to disallow on purpose (mostly around payment manipulation). If you hit a true blocker, contact Shopify Plus support they have a partner team for migration edge cases.
June 30, 2026 isn't a suggestion. It's a wall.
Every Shopify Plus store running Scripts needs to migrate to Functions. There's no workaround, no plugin that fixes this, and no more deadline extensions coming. The stores that act now will have a smooth transition, a faster checkout, and zero downtime. The ones that wait until June will be scrambling and their customers will feel it.
If you're not sure where to start, run the Scripts Customizations Report today. Know what you're dealing with. Then decide whether your team can handle it in-house or if you need a partner who's done this before.
At Huptech Web, we've been migrating Shopify Plus stores from Scripts to Functions since Shopify first announced the deprecation. We know the edge cases, the gotchas, and the fastest path from audit to deployment.
Need help with your migration? Book a free Scripts audit at Huptech Web. We'll tell you exactly what needs to move, how long it'll take, and what it'll cost. No surprises.