How to Create an A/B Test Using JavaScript

What is JavaScript?

JavaScript is a programming language that can run on many different browsers and platforms. JavaScript is one of the fundamental building blocks of web technologies along with HTML and CSS. It can perform many operations such as controlling dynamically generated content on a web page, capturing user interactions, creating animations, validating form fields on web pages, and transferring information between web pages. JavaScript can also run on a platform called Node.js, allowing the creation of server-side applications. By running JavaScript code on the server, Node.js shows that JavaScript is more than just a programming language not used only in web browsers.

What is an A/B Test?

A/B tests are used to measure the effect of different variables on websites or mobile applications. For example, variables such as the color or position of a button on a website can be tested. These tests are performed to understand user behavior and to improve the user experience of the website or mobile application. Using JavaScript to create A/B tests is a common method. With this method, you can compare the performance of two different versions and determine which version is better. In this article, I will provide a step-by-step guide and examples for creating an A/B test.

What are the steps to create a test?

1. Open Developer Tools on our browser and select the element we want to change from the "Element" section.

2. After selecting our selectors, we test whether our JavaScript codeß manipulates the right place by pasting it into the "Console" section. We mostly use Vanilla JavaScript or a JavaScript-based library called jQuery.

3. If everything is as we want, open Google Optimize and create our test.

4. We create our variant and click the "Edit" button in the variation section.

5. In the opened page, we select the "Global JavaScript" option in the red area within "< > ". We paste our JavaScript code into the window that appears in front of us and click the "Apply" option. Then we click the "Save > Finished" buttons in order.

6. In the lower section, we put the conditions of the URL or path where we want it to work in the "Page Targeting" section. In the "Audience targeting" section, we can target various devices, set cookie conditions, and write Custom JavaScript. This is a very diverse section. For more information: Google Optimize Targeting.

7. After editing our conditions and targeting, we start our test by clicking the "start" button.

8. We can also edit the end date of the test from the right-hand side when we click the "Edit" button. If we want to end the test, we need to click the "End" button.

By following these steps, we have opened our A/B test.