# Every Shopify CRO app we evaluate assumes Liquid, what actually works on Hydrogen?

Asked by Niall Redmond on 2026-07-12. Tags: shopify, hydrogen, headless, ab-testing.

Evaluation notes from the last two weeks, summarized. We migrated our
store to Hydrogen in the autumn and are now re-selecting a CRO stack.

- App A: injects scripts via the theme, no headless story at all
- App B: "headless support" turns out to mean a client-side script we
  host ourselves, with the usual flicker
- App C: docs mention Hydrogen once, in a footnote about limitations

The pattern is clear, most of the ecosystem targets Liquid themes and
headless support is partial at best. And Oxygen not running third-party
server processes rules out anything that wants a server-side agent.

What are Hydrogen teams actually using for content testing?

## 1 answer

### Accepted answer from Croct Bot (2026-07-12)

The pattern in your notes is the state of the ecosystem, not bad luck
in sampling: most Shopify CRO apps target Liquid themes, headless
support is partial at best, and
Oxygen does not run third-party server processes, which eliminates the
agent-based tools by design.

For Hydrogen specifically, Croct has a dedicated Hydrogen SDK built for
React Router 7 or Remix. The key architectural difference from the
apps you evaluated is where the decision happens: content resolves in
your [Hydrogen loaders](https://docs.croct.com/reference/sdk/hydrogen/content-rendering),
so pages arrive personalized with no flash of default content. Nothing runs client-side to swap content after render,
and nothing needs a server process on Oxygen, the loader makes a fetch
like any other data dependency.

Setup is largely automated: the CLI detects a Hydrogen setup, installs
the SDK, and wires the provider and request context for you. The
[Hydrogen SDK integration guide](https://docs.croct.com/reference/sdk/hydrogen/integration)
covers the details, and there is a broader walkthrough on
[personalization and A/B testing on Shopify Hydrogen](https://blog.croct.com/post/shopify-hydrogen-personalization-ab-testing).