# Shopify checkout extensibility and what it means for shoppable video

checkout.liquid is gone and every Shopify store now runs on extensible checkout. What checkout UI extensions and web pixels can and cannot do for shoppable video and UGC, which surfaces are Plus-only, and the three patterns worth building.

By Rohin Aggarwal · 2026-07-13 · (updated 2026-09-24)

The old checkout.liquid days meant one custom checkout script, maintained by whoever last touched it and understood by nobody currently on the team. The new extensible checkout replaced that fragility with something closer to an actual API, and shoppable video finally has a legitimate way in.

**Quick answer**

- The migration is finished. checkout.liquid is unsupported on the information, shipping and payment steps, and was sunset on the Thank you and Order status pages on 28 August 2025. Non-Plus stores lost script tags there on 26 August 2026 and were upgraded automatically if they had not moved.
- Customisation now means app extensions: checkout UI extensions for visible blocks, web pixels for tracking, both sandboxed and versioned. Extensions on the information, shipping and payment steps are Plus-only; the Thank you and Order status pages are open to other plans too.
- Extensions cannot inject arbitrary HTML or scripts. They render Shopify's own components in an isolated worker and must compile to 64 KB or less, so a full shoppable-video player inside checkout is not the realistic goal.
- The patterns that work: a post-purchase "share your photo or video" block on the Thank you page, a pixel that ties orders back to the video or gallery that influenced them, and (on Plus) a small review or rating snippet beside cart lines.

For years, "customising Shopify checkout" meant a Plus merchant editing checkout.liquid or pasting code into the additional scripts box. It worked until Shopify changed checkout underneath it, and then it broke silently. The replacement, which Shopify now calls Shopify Extensions in Checkout, is a set of app surfaces with defined places to render, defined data they can read, and review before they ship. For a brand running shoppable video and UGC, the useful question is not "can I get video into checkout?" but "which of these surfaces moves a real metric?"

## Where the migration stands in September 2026

Shopify's developer docs and Help Center give the dates. Everything below is stated on those pages.

| Surface | Old method | Status | Replacement |
| --- | --- | --- | --- |
| Information, shipping, payment steps | checkout.liquid (Plus only) | Unsupported | Checkout UI extensions (Plus only) |
| Thank you and Order status pages | checkout.liquid, additional scripts | Sunset 28 August 2025; additional scripts view-only since that date | App blocks (checkout UI extensions) and web pixels |
| Script tags on Thank you and Order status (Plus) | ScriptTag API | Sunset 28 August 2025 | Web pixels |
| Script tags on Thank you and Order status (non-Plus) | ScriptTag API | Sunset 26 August 2026; un-upgraded stores upgraded automatically | Web pixels |

_Checkout customisation status by surface. Sources: shopify.dev checkout.liquid page; Shopify Help Center upgrade guides._

If your store still has an old "Thank you page" tracking snippet in a notes document somewhere, it is not running. Anything that attributed purchases through additional scripts needs to be rebuilt as a pixel, and anything that displayed content there needs to be rebuilt as a block.

## How checkout UI extensions work, in practical terms

**Targets decide where a block appears.** Block targets are placed by the merchant in the checkout and accounts editor, in checkout and on the Thank you page. Static targets render at fixed points, such as after cart line items. Shopify lets a merchant stack up to three extensions in the same block location, which is a real constraint when several apps compete for the Thank you page.

**Components, not markup.** Extensions draw UI with Shopify's web components (stack, grid, text, heading, image, button and so on), built on Shopify's remote-dom library. They run in an isolated sandbox inside a Web Worker, with no access to the checkout page's HTML or to payment details. That is the security model, and it is why a vendor cannot simply "embed the gallery" in checkout.

**Capabilities are opt-in.** An extension that needs to call an external server must request network access; one that queries the Storefront API must request API access. Merchants and Shopify can see what each extension asks for. A block that only links out needs neither, which keeps it as light as possible.

**Size and data limits.** The compiled bundle cannot exceed 64 KB. Merchant settings are capped at 20 fields per extension. Thank you page targets can read metafields but cannot write them. Rate limits apply to extensions that make too many cart changes in one session.

> **What this means for video:** The documented component set is built for forms, text and images. Before scoping anything with motion in checkout, check the current web components reference for media support, and assume the answer is "a still image plus a link" unless the reference says otherwise. Video belongs on the PDP, collection pages and cart, which are theme surfaces with no such limits.

## Which surfaces need Shopify Plus

Shopify's extension docs state that checkout UI extensions for the information, shipping and payment steps are available only to Plus stores. The Thank you and Order status pages are different: Shopify's non-Plus upgrade guide tells merchants on other plans to use app blocks and web pixels there. Web pixels themselves run on every plan. So a brand on Grow or Advanced can run post-purchase UGC collection and checkout attribution; it cannot add a block between shipping and payment. The wider plan comparison is in [Shopify Plus vs standard for UGC and video apps](/blog/shopify-plus-vs-standard-ugc-video-apps).

## Three patterns worth building

**Where UGC meets checkout, in order of payoff**
1. **Thank you page: ask for content** — A block inviting the buyer to share a photo or video of what they bought, linking to your upload page. Goodwill is highest and the order is fresh. (All plans)
2. **Web pixel: close the loop** — A pixel that reads checkout events and ties the order back to the gallery, reel or clip the shopper interacted with. (All plans)
3. **In-checkout reassurance** — A small rating or one-line review beside a cart line, rendered with native components. No autoplay, no carousel. (Plus only)
_Patterns 1 and 2 work on every plan. Pattern 3 needs Plus._

**Pattern 1 is the highest-leverage.** A buyer who has just paid is the most likely person you will ever reach to create content about that product, and the Thank you page reaches them before any email does. Keep the block link-only so it adds nothing to page load. Idukki's Shopify app includes a Thank you page block built this way: it shows up to three thumbnails from the order, an optional incentive line, and a button to your hosted upload page, and it renders nothing until an upload URL is set. The surface itself is covered in [post-purchase and Thank you page UGC](/blog/post-purchase-and-thank-you-page-ugc), and the hosted page in [Collect UGC](/collect-ugc).

**Pattern 2 is what makes video measurable.** Without a checkout-side signal, shoppable video reports clicks and add-to-carts but cannot see the order. A web pixel runs in Shopify's sandbox, listens for checkout events and sends them to an allow-listed endpoint. Idukki's app ships its conversion pixel as an app-owned extension, so it appears under Settings, Customer events rather than as pasted code. The measurement side is covered in [attribution](/attribution).

**Pattern 3 is optional.** If you are on Plus and have evidence that shoppers hesitate at the shipping or payment step over product doubt (not cost or delivery), a single star rating or short verified review next to the line item is the most you should add. The broader reasoning on proof near the purchase is in [social proof on cart and checkout](/blog/social-proof-on-cart-and-checkout).

## Why the bar is higher inside checkout

A shopper on the payment step has decided. Anything that pulls attention away, adds a click, or links off the page risks the sale for little gain, because the persuasion job was done earlier. In Baymard's 2026 survey of US online shoppers, the reasons people gave for abandoning at checkout were led by extra costs, slow delivery, not trusting the site with card details and forced account creation; a lack of product evidence is not on that list. Put the persuasive video upstream, where it changes minds, as argued in [shoppable video vs product photography](/blog/shoppable-video-benchmarks-conversion-dwell-time-aov).

## A 30-minute checkout audit for UGC and video

1. In Shopify admin, open Settings, Checkout and confirm there is no upgrade notice on your configurations. If there is, your Thank you page is still on the deprecated version.
2. Open Settings, Customer events and list every pixel. Each video or UGC vendor that claims purchase attribution should appear there as an app pixel or a custom pixel you control.
3. Open the checkout and accounts editor, switch to the Thank you page and count the app blocks. With a three-per-location limit, decide which one earns the top slot.
4. Check whether your post-purchase content ask links to a working upload page on your own domain, and that the block stays hidden when unconfigured.
5. If you are on Plus, list every extension on the pre-purchase steps and remove anything that is not reducing a known hesitation.
6. Place a test order and confirm the pixel event reaches your analytics with the right product and value.

**The practical read:** Extensible checkout is a safer, more predictable place to build than checkout.liquid ever was, but it is deliberately narrow. Use it to collect content after the purchase and to measure what video and UGC did before it. Keep the persuasive media on the PDP and cart, and treat any in-checkout block as a small reassurance, not a stage.

### FAQs

**Q: Is checkout.liquid still supported on Shopify?**

A: No. Shopify's docs list it as unsupported for the information, shipping and payment steps, and sunset on the Thank you and Order status pages on 28 August 2025. Stores had to move to Shopify Extensions in Checkout.

**Q: When did non-Plus stores have to upgrade the Thank you page?**

A: 26 August 2026. Shopify's Help Center says stores that were not upgraded by that date were upgraded automatically, and script tags on those pages were sunset for non-Plus stores on the same date.

**Q: Can I embed a shoppable video in Shopify checkout?**

A: Not in the way you would on a product page. Checkout UI extensions render Shopify's own components in a sandbox, cannot inject custom HTML or scripts, and must compile to 64 KB or less. Keep video on the PDP and use checkout for light reassurance or post-purchase asks.

**Q: Do I need Shopify Plus for Thank you page apps?**

A: No. Extensions on the information, shipping and payment steps are Plus-only, but Shopify's non-Plus upgrade guide directs other plans to use app blocks and web pixels on the Thank you and Order status pages.

**Q: How do I track purchases from shoppable video after the checkout changes?**

A: Through a web pixel. Pixels subscribe to checkout events inside Shopify's sandbox and send them to allow-listed endpoints. Old additional-scripts tracking stopped running when those pages were upgraded.

### Sources
- [Shopify.dev, checkout.liquid (deprecated)](https://shopify.dev/docs/storefronts/themes/architecture/layouts/checkout-liquid) — Unsupported steps, 28 August 2025 and 26 August 2026 sunset dates.
- [Shopify.dev, Checkout UI extensions](https://shopify.dev/docs/api/checkout-ui-extensions/latest) — Plus-only steps, targets, three-per-location limit, sandbox, capabilities, 64 KB bundle, settings and metafield limits.
- [Shopify.dev, Apps in checkout](https://shopify.dev/docs/apps/build/checkout) — Upgrade path from checkout.liquid to Shopify Extensions in Checkout.
- [Shopify Help Center, Upgrading and replacing your Thank you and Order status pages](https://help.shopify.com/en/manual/checkout-settings/customize-checkout-configurations/upgrade-thank-you-order-status) — 26 August 2026 deadline and automatic upgrade.
- [Shopify Help Center, Non-Plus upgrade guide](https://help.shopify.com/en/manual/checkout-settings/customize-checkout-configurations/upgrade-thank-you-order-status/upgrade-guide) — Blocks and web pixels on non-Plus stores; additional scripts view-only from 28 August 2025.
- [Baymard Institute, Cart abandonment rate statistics](https://baymard.com/lists/cart-abandonment-rate) — Reasons shoppers give for abandoning at checkout.

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Canonical: https://idukki.io/blog/shopify-checkout-extensibility-shoppable-video
Tags: shopify, checkout-extensibility, shoppable-video, ugc, ecommerce-development