Review and demo of GTMtesting.com

Recently, I was given a demo of the GTMtesting.com tool. With this (Free!) tool, it’s super easy to do A/B testing with Google Tag Manager.

In this post, I will show you what it is and how it works.

What is GTMtesting.com?

From their site:

GTM testing offers a simple and elegant solution to AB testing in Google Tag Manager. And it’s free for unlimited tests and pageviews.

Sounds great? It does! I’ve created a screencast demo’ing the whole process. It’s about 8 minutes long.

Demo

Here’s how it works (in words)

1. You need a GTM testing code snippet on every page you test on
   This snippet can be put in a tag with a special trigger which is only triggered on running experiments. You won’t load the script when it’s not needed.
2. You then create an experiment using the GTM testing interface
   This is very easy, BUT there’s one catch: you should have the JavaScript source code for each variation ready. It’s not WYSIWYG.
3. GTM testing will create the complete JavaScript code that you can put in an experimentation tag.
   You decide on what pages the experiment is run, using a trigger. The generated code will then trigger the code snippet (see first bullet) and the the experiment is running!

Pros and cons

Here’s my opinion about the pros and cons of this new tool.

• Pro: It works. Plain and simple.
• Pro: It’s free.
• Con: It’s using an external script. But that said: you can always host a local copy
• Con: You have to code the variations yourself, or use a visual tool like VWO or Optimizely and retrieve their generated code.
• Con (or Pro, if you’re a Pro): There’s is no dashboard to look at the results of your tests. Actually, this is a good thing, since you should definitely always use your analytics tool to evaluate your test results.
• Pro: it has Google Analytics integration. For other tools, you need to put measure code in your variation code.
• Con: it’s not as fast as a properly implemented test-tool can be. You might suffer the dreaded flicker effect.

Roundup and verdict:

I find it’s a very good tool to test small changes (e.g. changes in copy, styling changes, etc). Especially on high-traffic websites where you have hundreds of thousands of visitors it just plain works and won’t cost you an arm and a leg in licensing fees.

When testing big variations where the expected flicker effect might be an issue: test it out to see if it works for your case. Finally, when you have complicated setups, or want to do redirect-tests, you still need a full specialised AB test tool.

So.. your turn: please check out the tool yourself, and if you have any questions or remarks about my review, please leave a comment.

Related posts:

Detecting Incognito Mode and using it in Google Tag Manager Properly Analyze A/B Test results with Advanced Segments Set up A/B tests using the Google Tag Manager Catch exit-intent with a Google Tag Manager trigger