Top 8 AB Testing Metrics to Track in 2025

Here’s a brief overview of everything this article entails:

A/B Testing Metrics: Data points used to determine the effectiveness of your A/B tests, identify successful variants, understand the reasons for results, and make informed decisions.

Choosing the Right Metrics

Key AB testing metrics:

How to improve the key AB testing metrics:

Top A/B Testing Tools

• Fibr AI

• VWO

Let’s start with the basics.

A/B testing metrics are the data points that help you determine how effective your hypothesis was, which variant was most successful, what led to the results you achieved, and eventually make informed decisions.

Say your goal is to improve the conversion rate, i.e., increase the number of users who click the signup button.

Now, you create a hypothesis according to which changing the color of the CTA would help you increase the conversion rate.

You keep the color of the CTA button green for variant A and yellow for variant B.

Upon running the test and analyzing the results, you come to know that variant B performed better, i.e., drove more sign-ups.

Based on the results, variant B brought a higher conversion rate, which you decided to make live.

Because you tracked the required metrics, you could:

One of the best ways to choose the right A/B testing metrics is by mapping your users’ journey right from when they interact with your website or page to the moment they leave.

Here’s an example:

Say you want to boost sales of your product, and you create 2 variations for A/B testing. Variation A has a traditional layout, while version B has a modern design with more product images and the “ Buy Now ” button positioned differently.

Now, to determine what metrics to track, you need to map the user journey:

Identify Key Interaction Points

Selecting Metrics and KPIs

This will help you determine if the new UI holds the attention for longer.

By mapping the user journey, you can identify the points where users make decisions. This helps you pick the metrics that reflect those actions/decisions.

Say if the CTA placement in variation B increases your CTR but doesn’t improve checkout completions, you’d know to focus on the checkout process and the related metrics next.

The key A/B testing metrics you need to track include conversion rate, click-through rate, bounce rate, scroll depth, average order value, average session duration, and abandonment rate. Let’s discuss these metrics in detail:

1. Conversion rate

The conversion rate is pretty broad and the most obvious metric to track to determine the success of your conversion rate optimization efforts. The higher the conversion rate, the better it is.

However, you need to define what you consider as a conversion. For instance, it could be a form submission, a sign up, a demo request, or something else.

According to Ruleranalytics, here’s the average conversion rate by industry:

How to calculate conversion rate:

Conversion rate = (Number of conversions/ total number)*100

How to improve the conversion rate?

The answer to this largely depends on what you’re considering a conversion.

Say, for you, a customer making a purchase is a conversion. Now, you need to track the users’ journey to understand what is stopping them from taking action. And for that you need to track other secondary metrics, such as the bounce rate.

For instance, if the bounce rate is too high, you may want to work on it by making the content more engaging or relevant to the audience. When you improve the bounce rate, you’ll be able to keep the users on the website, which may eventually improve your conversion rate.

1. Click-through rate (CTR)

Click-through rate or CTR is another important AB testing metric that represents the percentage of people who clicked a link or a digital asset against the number of people who viewed it.

Let’s say your ad was viewed by 100 people, but only 10 clicked and landed on your landing page. Now, your CTR would be 10% (10/100*100). And out of those 10, only 2 clicked your landing page CTA, now, your click-through rate would be 20% (2/10*100).

A lower CTR indicates problems with your CTA or other visual elements like an image, video, or event text copy.

How to calculate Click through rate (CTR):

Click-through rate = (clicks/impressions)*100

How to improve the click-through rate?

Here’s how you can improve your CTR:

1. Bounce rate

Bounce rate tells you the percentage of visitors who landed on your website but bounced right off without taking any action.

The lower the bounce rate, the better. According to HubSpot, the average bounce rate ranges from anywhere between 26%-70%. If your bounce rate is somewhere within this range, it’s great.

However, if the bounce rate of your landing page exceeds 70%, it indicates issues with your page quality, content, and UX. Common issues may include:

How to calculate bounce rate:

Bounce rate = (one-page visits / total visits)*100

How to improve the bounce rate?

To improve your bounce rate, you can:

1. Scroll depth

Scroll depth tells you how far a user scrolls down a landing page or web page. Lower scroll depth indicates a lack of engagement across the page or after a certain point because of poor design and irrelevant content, among other issues.

By tracking scroll depth, you can also determine the average content length that is appropriate for CTA placement.

If most of your visitors don’t scroll past a point, even if there aren’t any issues, you can place the CTA above that point to ensure more clicks or conversions.

How to calculate scroll depth:

You can set a scroll depth trigger in Google Analytics for automated tracking. However, if you wish to calculate the value, you can use this formula:

Scroll depth = (furthest scroll point in pixels/total pixel page height)*100

According to Agency Analytics, good scroll depth ranges between 60-80%. However, a higher scroll depth may not necessarily be a good sign, especially when you compare it with other metrics.

For instance,

To improve your scroll depth:

1. Average order value (AOV)

Average order value (AOV) tells you how much a customer spends on your website during a single purchase. This metric is particularly important for eCommerce businesses as it helps you evaluate if the changes you made persuaded the customers to spend more or not.

Another reason to track the average order value is to determine which version is actually good from a revenue perspective. How?

Imagine your variant A has an “add to cart” rate of 3X, while variant B has an “add to cart” rate of 5X. Without factoring in the AOV, you’ll declare variant B as the winner.

However, upon tracking AOV, you find out that the average order value of variant A is 4 times that of variant B. This means that variant A is driving more revenue and thus should be declared as the winner.

How to calculate average order value (AOV):

Average order value = (total revenue / total number of orders)

How to improve the average order value (AOV)?

Improving your average order value means convincing your customers to spend more per purchase on average. And to achieve this, you can:

1. Average session duration

Average session duration is the time a user spends on your website during a single visit. The session is measured right from the moment the users enter your site until they become inactive or leave your site.

If a user spends more time per session on your website, it indicates that they find your website valuable and they’re getting what they came in for. While you may not exactly know what is making them stay, you’d get an idea that you’re doing something right.

In a nutshell, by tracking average session duration, you can determine which page your audience is finding more engaging or interesting.

How to calculate average session duration:

You can find the average session duration from Google Analytics.

However, if you want a formula, here you go:

Average session duration: total session duration / total sessions

How to improve the average session duration?

To improve the average session duration, you need to understand where and why users are dropping off.

For that you can leverage Hotjar’s screen recording feature. This feature records the interaction of every user with your landing page element, allowing you to understand the user journey better. And when you can view/understand the user journey, you can make necessary improvements.

For instance, if users are not interacting with your CTAs, you can change its placement or make it more dominant. Or if the users are getting attracted to a particular section, you can place more valuable information there.

1. Abandonment rate

Cart abandonment rate gives you the percentage of users that added items to their carts but did not end up making a purchase against the total number of users that added items to their carts.

However, when you talk about the abandonment rate alone, it includes any action that was initiated but wasn’t completed. It could be filling out a form or a survey, etc.

A higher abandonment rate indicates a bad user experience, which could stem from lengthy forms, forms asking for personal information, unfavorable payment options, or a high delivery fee.

How to calculate abandonment rate:

Abandonment rate: (number of intended tasks completed / total number of tasks initiated) *100

How to improve the abandonment rate?

Here’s how you can improve abandonment rate:

1. Retention rate

When it comes to A/B testing, retention rate is the percentage of users who return to a landing page after a period of time. This user behavior metric tells you how effective a landing page is. It also helps you determine which audience segment is more likely to convert.

How to calculate retention rate:

Retention rate: (number of returning visitors within a period of time / total number of visitors that landed on the website during the same period)*100

How to improve the retention rate?

Users may have left the page for several reasons, such as:

Your goal is to bring the users who’ve viewed your page back. Here’s how you can achieve this goal:

Now that you have a basic idea of AB testing metrics to track, you can start analyzing your A/B testing results. Afterall, that’s why you were tracking the metrics in the first place, right?

The best AB testing tools to conduct comprehensive AB tests and track the AB testing metrics include Fibr AI, VWO, Optimizely, AB Tasty, and Unbounce.

1. Fibr AI

Fibr AI is an AI-powered personalization platform that comes with a dedicated A/B testing tool.

Fibr AI’s A/B testing tool integrates seamlessly with Google Analytics 4, allowing you to track almost all AB testing metrics or KPIs mentioned in the above list.

Notable features

This CRO agent helps you validate your hypothesis or create new ones powered by accurate data. You can also perform multivariate testing using this tool.

P.S. If you want to automate the process of conducting and analyzing A/B tests on your website or landing page and need a tool that learns from the results and helps you implement best-performing strategies, try our Fibr AI.

1. VWO

VWO also comes with an A/B testing tool that allows you to conduct A/B testing, split URL testing, and multivariate testing. It uses the Bayesian-powered SmartStats engine to ensure you get reliable and real-time reports.

Using VWO, you can track the necessary KPIs or AB testing metrics and analyze the same to draw actionable insights.

Testing type: A/B testing, split URL testing, and multivariate testing

Pricing: The starter plan is free for up to 50,000 monthly tracked users.

Optimizely is a digital experience platform that comes with content management, advanced personalization engines, and web experimentation. It allows you to perform omnichannel experimentation and track the right AB testing metrics.

Optimizely supports A/B testing, split URL testing, and multivariate testing and leverages the Bayesian and Frequentist statistics model.

Testing type: A/B testing, split URL testing, and multivariate testing.

Notable features:

Pricing: Contact the sales team for pricing.

AB Tasty is an experience optimization platform that helps you with web and feature experimentation and allows tracking of all the necessary AB testing metrics.

Unbounce is a landing page builder and a CRO platform that also supports A/B testing, real-time analytics, and AI-driven tools for copywriting and optimization.

Testing type: A/B testing and multivariate testing.

Pricing: The plan that supports A/B testing starts at $112 a month

Now that you have a list of the best A/B testing tools, you can conduct A/B tests, compare your AB testing metrics, and make informed decisions.

If you wish to start right this instant, and that too for FREE, and leverage the power of AI to automate testing and optimization, try Fibr AI.