> For the complete documentation index, see [llms.txt](https://docs.intelligems.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.intelligems.io/content-experiences/content-experiences-overview/how-to-set-up-a-theme-change-experience.md).
# How to set up a Theme Change Experience
A Theme Change Experience serves visitors an entirely different theme instead of changing content on the existing one. It's the best fit for the biggest structural changes, comparing two fundamentally different site designs or builds, rather than something achievable with targeted edits or a single page swap.
### **1. Create the** Experience
From the Intelligems app, click **Create New Experience**, give it a name and description, and select **Theme change**.
### **2. Choose: Test or Personalization**
* Running it as a Test?
* Rename the Test and add a Description. This is optional and internal only, but tests can stay live for weeks, so the more detail here, the more your future self will thank you.
* Click the **+** button to create a group for each variation (2–5 groups) and name them.
* Use the slider to set the traffic split for each group.
* Click **Next Step** when you're done.
* Note: the more groups you add, the longer it'll take to reach statistical significance.
* Running it as a Personalization? Skip groups entirely. You're building one always-on theme for your targeted audience.
### **3. Select your themes**
Select the theme you'd like to use for each group.
* Make sure the Intelligems script is installed in every theme you're testing; this is what hides the preview bar at the bottom of the theme. If you use checkout.liquid, install the script there too so the preview bar is hidden at checkout (if you don't use checkout.liquid, this happens automatically).
* Product page templates are set at the product level, and the template name must exist in the live theme. If you're testing two different themes, make sure the template names match across both, so the templates you've chosen for each product exist in both themes. Preview your test theme(s) to confirm product pages look right before launching.
### **4. Set targeting (optional)**
For a Test, a visitor's group is assigned on their first visit and stored via a first-party cookie, so they'll see the same theme on repeat visits during the test.
For a Personalization, everyone who matches your targeting sees it every time.
Either way, you can narrow who's included in several ways, all under the [Audience](/general-features/targeting/audience-targeting.md) option unless noted:
* UTM parameters
* JavaScript expressions
* Device type (mobile or desktop)
* New vs. returning visitors
* [Mutually Exclusive Experiments](/general-features/targeting/mutually-exclusive-experiments.md) prevent visitors from being targeted by related experiments at the same time, to avoid interaction effects
### **5. Configure analytics**
What you configure here depends on which path you chose in step 2:
* Personalization? Add any [Custom Metrics](/analytics/overview/custom-events.md) you want to track, beyond the built-in ones.
* Test? Choose your Key Metrics and Primary Metric to measure against your control group, plus any [Custom Metrics](/analytics/overview/custom-events.md).
### **6. Preview and activate**
Preview your changes on the live site, then activate. The [Content Experience QA Checklist](/content-experiences/content-test-qa-checklist.md) has a Theme Change section worth walking before you start.
When you're ready to end it, [Ending a Theme Experience](/content-experiences/content-experiences-overview/how-to-set-up-a-theme-change-experience/ending-a-theme-test.md) covers what to do with the draft themes, and [Rolling Out Tests](/general-features/rolling-out-tests.md) covers making a winner permanent.
{% hint style="warning" %}
**Note:** Once your test ends, don't delete any theme that was included in it for at least two months.
Visitors who were in a test group have a session cookie that tells their browser which theme to load. If they return while that cookie is still active, Shopify will load the draft theme first, then Intelligems resets them back to the live theme, but only if that draft theme still exists. If it's been deleted, Intelligems never gets the chance to reset them, and the visitor sees a Shopify error instead.
Leaving tested themes in draft mode for a while after the test avoids this.
{% endhint %}
***
### FAQs
Why am I redirected to a different theme when I preview in Shopify Admin?
If you preview a theme in Shopify Admin that's part of a live theme test, you may be redirected to a different theme.
For example, if the control group is Theme 1 and the test group is Theme 2, previewing Theme 2 without an existing group assignment will randomly assign you to a group. If you land in the test group, you'll stay on Theme 2; if you land in the control group, you'll be redirected to Theme 1. From there, previewing Theme 1 will redirect you back to whichever theme matches your assigned group.
To preview a specific theme regardless of your assignment, use the Intelligems preview widget to switch groups.
Why am I still being redirected after my theme test ends?
This happens once per theme to make sure anyone who was assigned a preview theme during the test doesn't stay stuck there after it ends. After that first redirect, you'll be able to preview the theme normally through Shopify Admin.
Can I run a theme test and a price test at the same time?
We don't recommend run ing a Theme Change experience and a Price Change experience over the same traffic at the same time.
Two reasons. You lose the ability to read either result, because when conversion or profit per visitor moves, nothing in the data tells you whether the theme or the price moved it. And it doubles what you have to maintain. Price testing needs its [integration](/pricing-experiences/price-testing-integration-guides.md) present in every theme the experience can serve, so a variant theme missing it shows shoppers the wrong prices and corrupts both sets of results.
If you want both answers, run them one after the other.
{% hint style="warning" %}
Already running both? Confirm the price-testing integration is live in every\
theme in the Theme Change experience, including the drafts. It covers theme-level\
changes such as price tags on your product templates and cart update handling,\
and the base script alone doesn't provide it.
{% endhint %}
---
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