Shopify Scripts Are Off: Your Functions Migration Path

Your checkout still loads. Orders still come in. But at some point a discount stopped coming off, a shipping option you had hidden came back, or a payment method you had blocked reappeared — and no error ever fired. If that sounds familiar, this is almost certainly why: on June 30, 2026, Shopify Scripts stopped running for good, and anything they powered quietly went with them.

This guide is the post-deadline triage — what broke, what replaces each piece, and what it costs to put it right, in merchant language rather than developer docs.

What Happened: Your Scripts Are Off

Shopify Scripts were small pieces of code that personalized the cart and checkout — a Plus-only feature run through the Script Editor app. When they were deactivated, nothing visibly broke: no error page, no admin alert, no popup. In the merchant community, the pattern is described plainly: Scripts that silently stopped “usually mean full-price checkouts, and customers rarely report it — they just leave.”

The shutdown happened in two dated steps, both confirmed on Shopify's own changelog and developer docs. Here is the sequence, so you know exactly where the line falls.

Find Out What You Were Running

Before you fix anything, name what broke. Every Script fell into one of three official types, and each one shows its failure differently at checkout. Match the symptom you're seeing to the type below.

To see your own inventory, open your Shopify admin and go to Apps, then Script Editor, then Replace Shopify Scripts, then the Customizations report — do it now and write down every rule you had. That list drives everything that follows; the full step-by-step is in the recovery checklist below.

Shopify Functions: What They Are and Who Can Use Them

Functions do what Scripts did — custom discount, shipping, payment, and validation logic — but the delivery model changed. In Shopify's own words, Functions are “an improved and robust customization experience” that is “more user-friendly and accessible because they're distributed as apps,” and that “don't require users to interact with code.” For most merchants that means you install an app rather than write a Script.

That said, Functions are a newer platform than the Scripts they replace, and the setup can feel less direct than editing a Script did. A practitioner who has done these migrations puts the trade-off honestly:

Do You Need Shopify Plus?

This is the single most common point of confusion, so here is the exact rule. It splits along App Store apps versus custom apps you build.

The Replacement Map: What Replaces Each Script Type

Shopify published a direct mapping from each Script type to the Function API that replaces it; that document now redirects to the general Functions overview, so the pairing of each Script type with its no-code option below is ours. For merchants, the practical question is one level up: native setting, installed app, or a custom build? This table pairs the official API with the no-code option for each type.

For a plain percentage or amount-off Script, the native replacement lives right in your admin: automatic discounts apply in the cart and at checkout with no app at all, up to a maximum of 25 active automatic discounts. Anything with tiers or custom conditions, though, moves to an app or a Function. For the full mechanics of every discount type and how they stack, see our guide to Shopify discounts.

If your line-item Script ran a bundle deal, see where Shopify's free Bundles app stops before you pay for a bundle app.

B2B rules were among the most common Scripts — credit-limit checks, wholesale-only pricing, or blocking checkout under a condition. Those were validation and pricing logic, and they now rebuild on the Cart and Checkout Validation and Discounts APIs. If you run wholesale, our guide to B2B on Shopify Plus covers where that logic lives in the native B2B stack.

Which Recovery Route Is Yours?

You've seen the three types and what replaces each. Now answer five quick questions about what your Script did, how complex it was, and what help you have — and get the route that fits, from “fix it in settings” to “this one needs a developer.”

Your Post-Deadline Recovery Workflow

Whichever route fits your setup — native settings, an app, or a custom build — the first three steps are the same: find what you had, write it down, and decide what to keep. The split comes at step four: native readers configure the admin, app readers install a Functions app, and build readers brief a developer.

If a simple discount is bleeding money right now, a native automatic discount can plug that one rule in minutes as a stopgap while you work through the rest of the list. Tick each step off as you go; your progress saves on this device.

Apps That Replace Each Script Type

If your route is an app swap, these are current, Functions-based apps grouped by the Script type they replace. Prices are observed and tiers change, so confirm the current plan on each listing before you install.

Tiered and volume discounts are the clearest example of a rule that isn't native. On a standard direct-to-consumer store, Shopify's automatic discounts cover only amount-off, buy-X-get-Y, and free shipping — and native volume pricing exists only in the B2B channel. So a tiered discount Script becomes an app like Multiscount, or a custom Function. For the pricing strategy behind tiered and volume breaks, see our guide to Shopify dynamic pricing.

What It Costs and How Long It Takes

There is no official price list for this, and honest cost data is thin. The figures below come from individual agencies, not a survey — useful for orientation, not for setting a budget in stone. What is reliable is the shape of the choice: the simpler your logic, the cheaper and faster the fix.

Build It, Buy It, or Hire It Out

The honest decision is a gradient of complexity, not a single answer. The three routes below map to how much custom logic your rule actually needs — pick the lowest one that reproduces the behavior faithfully.

The math can justify a real build. One anonymized Plus merchant — a B2B-and-DTC hybrid — was losing an estimated €12,000–€18,000 a month in over-granted discounts and 80 hours a month of manual corrections before migrating. After a developer rebuilt the logic as four Functions over eight weeks, discount errors fell toward €200 a month and the team reported roughly €180,000 a year of recovered margin, against a €24,000 build and an €800-a-month retainer. Treat those as one store's numbers, but the shape holds: a broken rule can cost more than the fix.

How to Scope a Developer Brief

If your route is a custom build, a tight brief keeps the cost honest and the quotes comparable. You already have the raw material in your Script Editor report. A workable brief lists:

1. Every Script to rebuild, by type, straight from the Customizations report.
2. The exact rule each one applied — thresholds, tags, regions, conditions.
3. The edge cases that mattered, so nothing is quietly dropped.
4. The checkout scenarios a developer should test before you sign off.
5. Which parts need Plus, so custom-Function work is priced correctly.

Hand that list over and ask for a fixed scope against it, not an open-ended hourly estimate. For the full process of finding, vetting, and briefing someone, see our guide to hiring a Shopify developer.

Why Shopify Retired Scripts

Shopify didn't retire Scripts to make life hard. Scripts ran server-side inside the older checkout — a model Shopify has spent years replacing with one it describes as “app-based, upgrade-safe, higher-converting, and integrated with Shop Pay.” Functions are the logic half of that change; the checkout's front end moved at the same time. If your store also had theme-level checkout customizations, or you're untangling the broader checkout.liquid sunset, our guide to checkout extensibility maps that side of the shift.

The same replacement logic is playing out one layer further back in the store. Shopify deprecated legacy customer accounts in February 2026 — closed to new stores, no more feature updates, sunset date still unannounced as of October 2026 — and the customizations that lived in those account templates move to account UI extensions much the way discount Scripts moved to Functions. If your account pages were customized, our customer accounts migration guide is the equivalent triage for that stack.

If your store runs custom apps, a separate question is whether their REST Admin API calls need rewriting. That is a different deprecation with its own timeline, and our REST-to-GraphQL guide sorts out whether it costs you anything now.

The Bottom Line

There is no single “Scripts migration” that fits everyone. Your logic sets your route: a flat discount is a settings change, a standard rule is an app, and conditional or exact-behavior logic is a build. Get that one judgment right and the path is obvious — miss it and you either overspend on a developer you didn't need or keep leaking revenue you can't see.

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