Migration deadline for UI extensions to Preact + web components

[Riley_Draward]

I haven’t been able to find details about a deadline for UI extensions built with React to be migrated to Preact + Polaris web components.

The info in the linked ticket below (64 kb size limit starting with 2025-10 and the default React packages exceeding that) makes me think that it will be the standard 1 year of API version support for 2025-07 (the last API version to support React UI extensions), at which point all UI extensions will need to be moved over to Preact + web components - just hoping someone can confirm or deny this

Migrating to Preact + Web components is confusing and sloppy

Trying out the 2025-10 release this morning, and first off noticed checkout ui extensions must be under 64kb. This means switching to preact + web components to remain under that limit as vanilla react + ui react package add 73kb out of the box. Switched API version in toml, updated package.json to latest. This example fails out of the box: import '@shopify/ui-extensions/preact'; import {render} from 'preact'; export default function extension() { render(<Extension />, document.body); } …

Thanks for any assistance in advance, and apologies if I missed info in the docs!

[avocadomayo]

Hi @Riley_Draward, we cannot speak to plans to remove 2025-07 at this time, however as you pointed out, we do guarantee 1 year support for any API version, including 2025-07.

We encourage developers to invest in migrating since the smaller bundle size limit via Preact in 2025-10 can improve extension load time and lead to performance wins.