Script Tags Stop Running and the First Deadline Is October
On 24 August 2026 Shopify put a date on something that has been coming since 2021. Script tags stop running on 1 March 2027, and the ability to create or update them is blocked from 1 October 2026, which is about a month away. If your store loads any JavaScript through an app that uses script tags, that code has an expiry date now.
The two dates that matter
They do different things and the earlier one catches people out.
1 October 2026. The scriptTagCreate and scriptTagUpdate mutations start returning a user error, and the REST ScriptTag resource rejects POST and PUT. Existing script tags keep running, but nothing new can be created and nothing existing can be changed.
1 March 2027. Shopify stops injecting script tags into storefronts. Whatever is still relying on them stops loading.
The October date is the one to plan around, because an app that needs to update its script tag as part of normal operation effectively breaks then, five months before the headline deadline.
Pinning an old API version will not save you
This is worth stating plainly because it is the first thing a developer tries. Shopify's notice says the deprecation applies to all API versions, so pinning will not defer it.
That is a deliberate choice on their part and it removes the usual escape route. There is no version of the API where script tags keep working past March 2027.
How to find out whether this affects you
Most merchants have no idea whether their apps use script tags, because it is an implementation detail nobody surfaces.
The honest shortcut is to ask rather than investigate. Email every app vendor you pay and ask one question: does your app use script tags, and what is your migration plan for the October and March deadlines. A vendor with a plan will answer immediately. A vendor who goes quiet is telling you something useful.
The apps most likely to be affected are the older ones. Anything installed years ago that injects a widget, a popup, a chat bubble, a review badge or a tracking snippet is a candidate. Newer apps generally use theme app extensions already, because Shopify has been pushing that route since 2021.
If you have custom code built by an agency, the same question applies to whoever built it.
What replaces them
Two paths, depending on what the script actually does.
For anything that renders on the page, the replacement is an app embed block shipped in a theme app extension. That is a proper Shopify surface, it survives theme updates, and merchants can toggle it in the theme editor rather than having code injected invisibly.
For analytics and conversion tracking, the replacement is a web pixel. Shopify's guidance notes this needs no action from the app user, which matters if you are the one shipping the app.
If that split sounds familiar, it is the same division we saw with the checkout deadline in August: display goes to extensions, measurement goes to pixels. Shopify has been consistent about this for years now, and stores that already did the checkout rebuild will find the pattern recognisable.
Why this one is easier than the August deadline
Some good news, because the last few platform changes have been the other kind.
August's checkout change was yours to fix. The code sat in your Additional Scripts field and nobody else was going to rebuild it. This one mostly is not yours. Script tags belong to apps, so the migration is the app vendor's job, and for most stores the correct action is to confirm your vendors are on it and then update the apps when they ship new versions.
The work only lands on you where you have custom code, or where a vendor decides not to migrate and you need a replacement app. Both are worth finding out about in September rather than February.
What to do in September
- List every app that injects anything onto your storefront. Popups, badges, chat, reviews, trackers, banners.
- Email each vendor the same two-line question. Do you use script tags, and what is your plan for October and March.
- Ask your developer about custom code. Anything an agency added years ago is the likeliest place a raw script tag is still sitting.
- Keep the replies. In February you will want to know which vendors answered and which did not.
- Do not rip anything out yet. Script tags still work until March. Removing something early because it might break is how you create an outage you did not need.
How to read the answers you get back
Vendor replies to a deprecation question fall into three groups and they tell you different things.
The best answer names the dates back to you and says which release will handle it. That vendor is tracking the changelog and you can stop worrying about them.
The middling answer says they are aware and will handle it in due course. Fine for now, worth asking again in November. Put a note in your calendar rather than trusting your memory.
The answer to act on is silence, or a support agent who does not know what a script tag is. That is not proof the app will break, but it is a signal that nobody at that company is watching platform deprecations, and this is not the last one. If the app is doing something important, start looking at alternatives while you have five months rather than five weeks.
A sensible timeline
There is no reason to rush this and good reason not to leave it.
September is for the inventory and the emails. October is when you find out whether any app breaks because it needed to write a script tag, so keep an eye on anything that stops behaving normally in the first week. November and December are peak season and you should be changing nothing. January and February are when you replace whatever has not migrated, with a month of margin before the March date.
The one thing not to do is plan work for February on the assumption that everything will be fine. That is the month every other store will be doing the same thing, and app vendors and agencies will both be busy.
What are Shopify script tags?
A script tag is a way for an app to inject a JavaScript file into your storefront without touching your theme. They have been the standard mechanism for years, which is why so many older apps use them, and Shopify has been steering apps toward theme app extensions instead since 2021.
Will my store break on 1 October 2026?
No. October only blocks creating and updating script tags. Existing ones keep running until 1 March 2027. The risk in October is an app that needs to write a script tag as part of normal operation, which would fail from that date.
Can I keep using script tags by pinning an older API version?
No. Shopify states the deprecation applies to all API versions, so pinning does not defer it. This is different from most API deprecations and it removes the usual workaround.
How do I know which of my apps use script tags?
Ask the vendors. There is no merchant-facing screen that lists it, and inspecting your storefront source will not reliably tell you which app owns which script. One email to each vendor is faster and more accurate than any technical investigation you could run yourself.
What happens if an app vendor does not migrate?
That app stops working on your storefront in March 2027 and you need a replacement. This is the reason to ask now rather than later, because finding a replacement and migrating its data is a project, and doing it in February alongside everyone else is the expensive version.
Is this the same as the Shopify Scripts change?
No, and the names being almost identical is genuinely unhelpful. Shopify Scripts were Plus-only discount and shipping logic, and they stopped executing on 30 June 2026. Script tags are the app mechanism described here, they affect stores on every plan, and they run until March 2027.
Get your app stack checked
Free check. Email hello@exactwhy.com with subject "Script tags" and a list of the apps installed on your store. We tell you within 4 hours which are likely to be affected, which have already migrated, and which vendors have a track record of leaving this late. For most stores this is a handful of apps and a few emails.
Prefer a form? Send it through the contact page instead. It reaches the same inbox and you can attach whatever is useful.
Paid work, Rs 25,000 to Rs 1 lakh. We audit your storefront for script tag usage including anything custom, rebuild agency-built scripts as theme app extensions or web pixels, and test that nothing changed on the storefront.
Ongoing Shopify development, Rs 20,000 to Rs 50,000 a month. Including tracking deprecations like this one against what your store actually runs, which is the only reliable way to hear about them before the deadline.
The pattern from the last six months holds here too. Everything on our list of platform changes that broke things quietly was announced well ahead of time. What varies is whether anyone was reading.