The Shopify checkout extensibility deadline: what happens on 26 August 2026 The Shopify checkout extensibility deadline: what happens on 26 August 2026

The 30-second version

What stops: Additional Scripts on those two pages, the box your purchase pixels, GTM container and affiliate tags were pasted into, and app ScriptTags on the Order status page. shopify.dev on the second: "ScriptTags on the Order Status page have been deprecated and will be turned off on August 28, 2025, for Plus merchants and on August 26, 2026, for non-Plus merchants."

Replace both before the date and your conversion data survives. Miss it and purchase tracking goes quiet in September while your ad spend carries on as normal.

There are two deadlines, not one. 28 August 2025 was Plus, and it has passed. 26 August 2026 is everyone else. checkout.liquid is not part of your story: shopify.dev says it is "available only to Shopify Plus merchants." Any page telling you it disappears from a Basic or Grow store next month is wrong.

Check your admin. Thirty seconds.

Open Settings → Checkout and look at the Configurations section.

If a notice reads "Upgrade Thank you and Order status pages by August 26, 2026", that's the one. Click it, then click Review customizations. Shopify has already built you a personalised report of every customization it found on those two pages, and it lives at admin.shopify.com/settings/checkout/customizations-report. Shopify's guide describes what it does: "Your upgrade guide categorizes your additional scripts based on their purpose, such as authentication or order tracking."

No notice means you're already on the new pages and this deadline isn't yours.

Settings › Checkout › Configurations

Upgrade Thank you and Order status pages by August 26, 2026

Review customizations

No notice here means you are already on the new pages, and this deadline is not yours.

same screen, finished

Upgrade guide

admin.shopify.com/settings/checkout/customizations-report

Open upgrade report → Upgrade

Step 1 and step 6 are the same report, opened twice. Both labels are Shopify's.

A diagram, not a screenshot — Shopify's labels, drawn in Mtrix's own interface so nothing here can be mistaken for a capture of a real store.

The timeline

1. 6 Jan 2025 All plans Revert eligibility cut-off
2. 1 Feb 2025 All plans Apps can no longer create ScriptTags
3. 28 Aug 2025 Plus only Additional scripts and checkout.liquid can’t be edited
4. 28 Aug 2025 ALL PLANS The additional scripts section is view-only
5. 30 Jun 2026 Shopify Scripts users Line item, shipping and payment scripts stopped executing
6. 26 Aug 2026 Every plan except Plus Upgrade and replace your Thank you and Order status pages. ScriptTags turned off

The Shopify checkout extensibility timeline, 2025 to 2026

Date	Applies to	What happened / happens
6 Jan 2025	All plans	Revert eligibility cut-off. Only stores created before this date can undo an upgrade
1 Feb 2025	All plans	Apps can no longer create ScriptTags on Thank You or Order Status pages. Existing tags run until each plan's deadline
28 Aug 2025 ✅	Plus only	"your additional scripts and checkout.liquid can't be edited and Personally-Identifiable Information (PII) isn't accessible to your legacy pages"
28 Aug 2025 ✅	ALL PLANS	"As of August 28, 2025, the additional scripts section in the Checkout settings is view-only. You can no longer manually edit your additional scripts."
30 Jun 2026 ✅	Shopify Scripts users	"Any Scripts that were still published on your store have been deactivated and no longer work." A separate deprecation
26 Aug 2026 ⏰	Every plan except Plus	Deadline to "upgrade and replace your Thank you and Order status pages." ScriptTags "turned off on August 26, 2026, for non-Plus merchants." Revert window closes

All read 26 July 2026. Rows 2 and 6 (ScriptTags): shopify.dev/docs/apps/build/online-store/blocking-script-tags. Rows 3 and 6 (deadlines): the upgrade-thank-you-order-status parent page. Rows 1 and 4: its non-Plus upgrade guide. Row 5: help.shopify.com/…/script-editor.

The fourth row is what most write-ups get wrong. Your Additional Scripts box has been read-only on every plan since August 2025, eleven months ago. You can read what's in there. You cannot edit it.

Shopify Scripts is a different deprecation. Line item, shipping and payment scripts stopped executing on 30 June 2026, replaced by Shopify Functions. If your discount or shipping logic lived there, it hasn't run since June. A separate fire, and a hotter one.

What is actually date-certain on 26 August. App ScriptTags on the Order status page get turned off; shopify.dev names non-Plus merchants and that date explicitly. And the window to upgrade on your own schedule closes. What Shopify has not published is a blanket statement that every non-Plus store's pages are automatically replaced that day. Its one auto-upgrade sentence for non-Plus sits under the revert heading and addresses merchants who upgraded, reverted, and didn't upgrade again. Plan for "on or after 26 August," and don't rely on Shopify finishing the job for you.

Which plans count as non-Plus. Shopify's wording is "If you're on a non-Plus plan" and it names no individual plans. Its live plan list runs Starter, Lite, Retail, Basic, Grow, Advanced, Plus, Shopify for enterprise and Agentic. Whether Starter, Lite, Retail, Agentic and "Shopify for enterprise" stores follow 26 August is something no Shopify-owned page enumerated as of 26 July 2026 — and Shopify's checkout-apps page gates checkout-customizing apps at "the Basic Shopify plan or higher", so a sub-Basic store may never have had these customizations to replace. Ask your account team.

What it costs you, in the order you'll feel it

Shopify's word for the non-Plus path is replaced. There is no best-effort analytics migration for you; that language sits in the Plus auto-upgrade section only.

First you over-count. Shopify's own migration order creates a double-count window and says so: "When you install, connect, and test pixels to replace your additional scripts, duplicate events are tracked on the existing Thank you page, because the third-party platform counts events both from the script and from the app pixel." Install the apps and stop there, and you run inflated purchase numbers straight into August.

Then you go dark. The script stops. If the pixel was never finished, nothing replaces it. Meta, Google and TikTok allocate budget against the conversions they receive. They keep spending. They stop knowing what worked.

And there's a trap door. "If your Thank you and Order status pages are upgraded, then you can't reactivate your additional script." The revert path is narrow and it closes on the same date.

If you sell into Europe, your numbers then drop legitimately. Web pixels are consent-gated by design: "In markets configured to require consent (usually the European Economic Area (EEA) and the United Kingdom), web pixels run only when visitors have provided the permissions required in the pixel configuration. By default, new pixels require Marketing and Analytics permissions." Scripts pasted into a Thank you page fired regardless. If EEA and UK conversions fall after your upgrade, that isn't a broken pixel. It's the new floor.

We won't invent a dollar figure for you. Get your own: filter the last seven days of purchase events in Meta Events Manager and GA4, and count how many originate from Additional Scripts or an app's ScriptTag. That number is what goes quiet.

1

First you over-count

While both are live, every purchase is counted twice.

One purchase

Additional Scripts App pixel

2 events one order

Install the apps and stop there, and the inflated numbers run straight into August.

2

Then you go dark

The script stops. If the pixel was never finished, nothing replaces it.

Meta, Google and TikTok keep spending. They stop knowing what worked.

Schematic: no scale, no units, and the only number on it is the count of one order. The paragraph above refuses to invent a figure, so this refuses to draw one.

The upgrade, step by step

Shopify's five prescribed steps, plus three that get skipped. The two places you can get hurt are marked. Give it a mid-week afternoon, never a Friday.

1. Open your upgrade guide. Settings → Checkout → Configurations → Upgrade Thank you and Order status pages by August 26, 2026 → Review customizations.
2. Write everything down first. Every pixel ID, GTM container ID and affiliate tag. The box is read-only, so copy it out. That's your inventory and your rollback plan.
3. Handle compatible apps. Under Tracking and analytics, click Manage beside each app. Under Page customizations, click Add blocks.
4. Deal with incompatible apps. Shopify is blunt: "contact the app developer or install an alternate app." It tells developers the same thing: "we've observed merchants choosing to uninstall apps to unblock their upgrade." Expect one app to be why this takes longer than an afternoon.
5. ⚠️ Replace the scripts, then turn them off, in that order. Connect the pixel, run a real test transaction, confirm the event lands, then deactivate the script. Shopify's instruction is explicit: deactivate "after you confirm that the app pixel is sending events and the third-party platform is receiving them." Deactivating first creates a gap. Never deactivating creates the double-count.
6. Upgrade. From the Upgrade guide page, click Open upgrade report, then Upgrade. Same report you opened in step 1, finished. Two Shopify labels, one screen.
7. ⚠️ Buy something. Confirm checkout_completed lands in Meta Events Manager, GA4, your email platform and your affiliate network. Note that "Google Tag Assistant isn't compatible with custom pixels"; Shopify points you at its own tool instead: "Test the custom pixel to make sure the pixel is loading on your store and receiving events using the Shopify Pixel Helper." Test with a real order either way.
8. Rebaseline per market: seven days after against seven days before.

Budget half a day if your tracking already runs through official channel apps. Budget a week if you have a hand-built GTM setup, or apps whose developers haven't shipped extension support; most of that week is waiting on them. A month is enough. A month starting on 20 August is not.

What replaces what

What replaces each legacy checkout customization

What you had	What replaces it	Notes
GA4 / Google Ads in Additional Scripts	Google & YouTube app, included	Shopify marks it "Recommended" and "maintained by Google"
Meta, TikTok, Pinterest, Klaviyo, affiliate tags	An app pixel from Shopify's Customer events and conversion tracking collection, usually that vendor's own app	Priced by the app. Needs the vendor to maintain a current Shopify app
A GTM container	Google & YouTube app, or GTM rebuilt as a custom pixel	The pixel must contain checkout_completed, or purchase tracking disappears with no error
Banners, upsell blocks, messaging	Blocks, in the checkout and accounts editor, included	Every plan. Covers most design customizations
Session recording / heatmaps on those pages	An app from Shopify's curated Session recording and heatmapping collection	App subscription, varies. The sandbox limits below apply
Purchase attribution that sits on a page script at all	A server-side order webhook, which is how Mtrix reads Shopify orders	Separate platform subscription. Talk to us
Discount / shipping logic that used Shopify Scripts	Shopify Functions	Public Functions apps: any plan. Custom: Plus only. Already overdue

Rows 1–5 and 7: Shopify's replace-google-tag, customization-options and checkout-apps pages plus its own curated App Store collections, read 26 July 2026. Row 6 is Mtrix. Where Shopify points at a curated collection rather than a named third-party product, so do we.

What the new pages can't see

The new pages are sandboxed. That's deliberate and mostly good: arbitrary third-party JavaScript in a payment flow is exactly what Shopify is ending. Two parts of the trade surprise people.

The sandbox can't read the page. From Shopify's pixels overview, verbatim: pixel sandboxes "can't render user interface elements, such as buttons, forms, banners, or modals," and can't automatically detect events from DOM scraping, user information, such as email and phone, from DOM scraping, page scrolling, or clicks and mouse movement to create heatmaps from DOM scraping. Read that list twice if you run behaviour analytics.

Custom pixels are yours to maintain. Shopify's own guidance on the pixels overview is "Always ensure you understand the code that you add to your online store or store checkout, or hire a Shopify Partner for help with custom pixels," and on the custom-pixels page, "Not all pixel functionality works in the sandbox, and you might need to consult your third-party service provider for help." Rebuilding a GTM container as a custom pixel is a supported path, not a supported product.

To be fair to Shopify: that's a fidelity limit, not a blackout. The same overview page offers "you can publish custom events as an alternative," caveated with "Publishing custom events might not be supported by all app pixels." Somebody fires each event explicitly instead of a tool detecting it. Shopify also curates a session-recording and heatmapping collection for exactly these pages. Anyone telling you it's impossible to record sessions on Shopify is overselling.

Where a platform like Mtrix fits, and where it doesn't

Most readers should do the eight steps and get on with their week. This section is for the group asking a different question: why was my purchase data hostage to a script tag in the first place?

On the Shopify store you already have, Mtrix runs as an npm package or a CDN script and gives you session replay, analytics, experiments, error tracking and real-user performance monitoring. Two parts touch this deadline:

• Purchase attribution runs on a server-side Shopify Admin webhook (orders/paid, HMAC-verified). Not a checkout script. Not a ScriptTag. Nothing changing on 26 August touches it. Orders, line items and refunds land in Purchases with no pixel in the path. One honest condition: it needs a _mtrixSession note attribute on the cart. A wiring step, not magic.
• Ad attribution doesn't ride on a vendor pixel either. Mtrix captures first-touch click IDs (fbclid, gclid, gbraid, wbraid, ttclid) for 90 days and reads the ad platforms' own cookies on each event, without loading a vendor SDK. Sessions are captured at 100%, not sampled.

The concessions, which matter more than the pitch:

• Mtrix doesn't run inside Shopify's hosted checkout. Third-party code gets in there only through Shopify's own extension points: UI extensions, web pixels, post-purchase extensions, Functions. Mtrix ships none of them. Replay covers your storefront, not Shopify's checkout steps.
• Mtrix isn't a Shopify app. No App Store listing, no app pixel, no custom pixel. It won't appear in your upgrade report and it won't do the upgrade for you.
• Mtrix doesn't replace your pixels. Meta and Google still need their conversion events.
• Web only. No native iOS or Android SDK. Replay and errors are kept one month; events and purchases three years.

If your problem is a deadline, Mtrix is not the answer to it. If your problem is that four tools hold four definitions of a conversion and one of them just became a compliance project, that's worth a conversation in September, not this week.

Who should change nothing but the pages

• You have no Additional Scripts and no legacy app customizations. Your upgrade report will be near-empty. Click Upgrade, test one order, done. Fifteen minutes.
• Your pixels already run through official channel apps like Google & YouTube. Those are app pixels already, so you're most of the way there.
• You depend on niche Shopify apps for subscriptions, loyalty or your 3PL. That ecosystem is Shopify's deepest advantage and nothing on this page outweighs it. Chase your app developers; don't replatform in a panic.

A deadline is a terrible reason to change platforms. It's a fair reason to find out how much of your measurement is balanced on a script tag.

And yes, you can A/B test Shopify checkout now

Most pages on this subject still say you can't. Since 5 June 2026 you can: Shopify's changelog reads "Rollouts now supports scheduling, gradually publishing and A/B testing your themes and checkout and customer accounts configurations." Native, free, no app to install, Grow plan or higher.

It swaps one whole configuration for another and reports a single metric, checkout conversion rate. That's the right trade for one checkout test a quarter and the wrong one for a testing programme. The full capability boundary and the tools that go past it are in the best Shopify checkout A/B testing tools and what server-side testing actually is.

FAQ

Do the upgrade this week

26 Aug

Start this week A month is enough.

7 days of work 7 days to rebaseline 1 2 3 4 5 6 7 8

1 Aug → 15 Aug 11 days clear

Start 20 Aug A month starting on 20 August is not.

7 days of work 7 days to rebaseline 1 2 3 4 5 6 7 8

20 Aug → 3 Sep 8 days past the deadline

1. 1 Open your upgrade guide
2. 2 Write everything down first
3. 3 Handle compatible apps
4. 4 Deal with incompatible apps
5. 5 Replace the scripts, then turn them off, in that order
6. 6 Upgrade
7. 7 Buy something
8. 8 Rebaseline

Copy your Additional Scripts box into a document before you touch anything else. Then, once the fire is out, ask the better question: how much of your revenue reporting depends on somebody else's script tag continuing to exist?