GTM A/B Test Generator
Automate your A/B test setup. Generate a ready-to-import GTM container in seconds, not hours.
How it Works
This tool generates a GTM container (`.json`) with all the tags, triggers, and variables needed for a simple A/B test.
- A script assigns users to Group A or B.
- The element you specify is hidden for Group B.
- The user's group is sent to GA4 for analysis.
After generating, import the file into GTM via Admin → Import Container. Remember to choose the MERGE option.
Why Use This GTM-Based Approach?
The Benefits
- No Extra Cost: Leverages the tools you already use (GTM and GA4) without expensive platform fees.
- Site Speed: Avoids adding heavy third-party A/B testing scripts that can slow down your website.
- A Post-Google Optimize Solution: With Google Optimize now deprecated, this tool provides a free, straightforward alternative for running simple experiments.
- Empowerment: Allows marketers and analysts to launch simple tests without needing developer resources.
Our Approach to Limitations
- The "Flicker Effect": Our script is designed to run very early, minimizing the flicker for simple changes like hiding an element. However, for complex visual edits, dedicated platforms may still be superior.
- Test Complexity: This tool is perfect for straightforward tests (e.g., hiding an element, changing button text via a GTM variable). For multi-element or dynamic content tests, a full-featured platform is recommended.
- Data Analysis: This tool focuses on test deployment. The crucial analysis of results and statistical significance is performed within Google Analytics 4, which our setup fully supports.
Frequently Asked Questions
What does this tool do?
This tool automatically generates a ready-to-import JSON file for Google Tag Manager (GTM). This file contains all the necessary tags, triggers, and variables to run a simple A/B test, such as hiding an element for a percentage of your users.
Why should I use this instead of a dedicated A/B testing platform?
For simple tests (like changing a headline or hiding an element), a full platform can be overkill. This tool uses the power of GTM, which you likely already have on your site. It's free, lightweight, and avoids adding extra third-party scripts that can slow down your page.
How do I analyze the results of the A/B test?
The generated GTM container sends the user's group ("A" or "B") as a parameter to Google Analytics 4 (GA4). You can then create comparisons or segments in your GA4 reports to see how conversion rates and other metrics differ between the two groups.
Is this tool a replacement for platforms like VWO or Optimizely?
Not entirely. This tool is a lightweight alternative for simple A/B tests. Dedicated platforms like VWO offer advanced features like visual editors, detailed statistical modeling, and personalization engines that are better suited for complex, large-scale optimization programs.
How does this tool handle the 'flicker effect'?
The flicker effect happens when original content loads before the A/B test variation appears. Because this tool uses a script deployed via Google Tag Manager that fires quickly, the effect is minimized for simple tests like hiding an element. The user is unlikely to perceive any flicker.
See It in Action
Watch this short demo to see how to generate and import your container.