> For the complete documentation index, see [llms.txt](https://docs.abtasty.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.abtasty.com/recommendations-and-merchandising/how-tos/how-to-a-b-test-recommendation-strategies-using-ab-tasty-web-extensions.md).

# How to A/B test  recommendation strategies using AB Tasty Web Extensions

### Overview

The implementation relies on a clear separation of responsibilities.

#### AB Tasty side:

* Creates the A/B test
* Generates 2 variations: A and B
* Randomly assigns visitors
* Sets an experiment assignment cookie

#### Client or Agency side:

* Reads the cookie set by AB Tasty
* Interprets the assigned variation (A or B)
* Triggers the corresponding call to the Merchandising & Recommendation API

### AB Tasty Implementation

{% stepper %}
{% step %}

#### Create the test

Create an A/B test on the desired scope (product page, homepage, listing page, etc.) with two variations:

* **Variation A**
* **Variation B**

{% hint style="warning" %}
The test does not directly modify the recommendation block. It is only used to split traffic and set an assignment cookie.
{% endhint %}
{% endstep %}

{% step %}

### Set the assignment cookie

For each variation, AB Tasty sets a specific cookie identifying the assigned group.

Example:

* Group A → `ab_test_reco_1 = A` 
* Group B → `ab_test_reco_1 = B`

The exact cookie name can be adapted to your technical conventions.

This cookie is:

* Stored browser-side
* Accessible through JavaScript
* And allows the website to determine which variation the visitor belongs to
  {% endstep %}
  {% endstepper %}

### Client or agency implementation

{% stepper %}
{% step %}

#### Read the cookie

The website must read the `ab_test_reco_1` cookie.

Example:

```
const variation = getCookie("ab_test_reco_1");
```

{% endstep %}

{% step %}

### Conditional Recommendation & Merchandising API call

Depending on the cookie value:

* If `variation=A` → call Recommendation Strategy A
* If `variation=B` → call Recommendation Strategy B
  {% endstep %}
  {% endstepper %}

### Technical considerations - execution timing

The experiment assignment cookie must be read:

* After the AB Tasty script has been executed
* Before triggering the Merch & Recos API

### Notes

| AB Tasty Side      | Client Side          |
| ------------------ | -------------------- |
| Test creation      | Cookie reading       |
| Traffic allocation | A/B interpretation   |
| Cookie assignment  | Conditional API call |

* AB Tasty manages the experimentation layer
* The website controls which recommendation strategy is called


---

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