A/B testing can make a startup scale faster – or fail faster. And both these options are good. Why? Because A/B testing eliminates the guesswork. Even if the stakes are not quite that dramatic and you're just deciding on the right button color, you test everything and either keep going or you move on to the next hypothesis. No more wandering in the woods.
A/B testing is a crucial technique in product design and marketing – and especially so in the competitive SaaS landscape. What is A/B test, why is it so important, and how to use it? We prepared the material to answer all of these questions. And if you prefer to watch, check out our YouTube video on the topic.
What is A/B testing?
Also known as split testing, this is a method where two versions of a web page or app are compared to determine which one performs better. It's like having two teams play the same game under slightly different rules to see which strategy wins.
Imagine you’re at a fork in the road on your product design journey. One path is your current design (let’s call it A), and the other is a new idea you think could work better (that’s B). A/B testing helps you choose the path that leads to more engagement, better user satisfaction, and of course, higher conversions.
Why A/B testing SaaS is essential
In the digital world, even minor changes can lead to significantly different outcomes. A shifted button or a new color on a call-to-action can increase user interactions and conversions dramatically. A/B testing provides a risk-free way of testing these changes before full implementation, ensuring that data, not guesswork, guides decisions. For instance, if a SaaS platform considers altering its product page layout to boost subscriptions, A/B testing allows them to test the new layout against the original with real users, gathering concrete evidence on which performs better. This data is a core component of your UX audit checklist, providing empirical proof for design recommendations. So, what are the specific reasons to use A/B testing?
Better user experience
A/B testing lets SaaS companies carefully improve how users see and use their products. By comparing two versions of something, like a web page or a feature, companies can find out which one users prefer. This leads to a product that's easier and more enjoyable to use, which means users will likely use it more and stick around longer. Often, the best way to get insights from usability tests is to see which version reduces friction in real-time.
Higher conversion rates
A/B testing conversion increase is one of the main goals. A big goal of testing in SaaS is to get more users to sign up or subscribe by making the product more appealing. For example, testing pricing page designs can show which version encourages more people to sign up or upgrade. By tracking specific usability metrics like time-on-task and conversion funnels, companies can make better offers that meet users' needs and increase sales.
Less risk and lower costs
Making changes to a product can be risky and expensive if those changes are based just on guesses. A/B testing reduces this risk by allowing companies to test changes on a small scale before applying them to everyone. This is particularly effective when combined with remote usability testing, as you can observe global users interacting with new features in their natural environment without a full-scale launch. This way, companies avoid spending money and effort on ideas that don't work, saving resources and reducing the chance of making costly mistakes.
Faster iterative development
In the agile development environment typical of many SaaS companies, A/B testing is important for fast and ongoing improvements. It helps companies continuously refine their products based on what users like and don’t like. This quick adjustment keeps the product relevant and appealing, giving the company an edge over competitors.
For example, when Eleken's designers were working on designing Prift, a personal finances platform, they decided to test their hypothesis with the users only on. They created wireframes with different layouts for one of the most important screens and presented them to potential users to learn which corresponds better with their needs, expectations, and pain points.
Users choose the second screen, which allowed our designers to move to the next stages of design with more confidence. Taking the time to fix UX issues early through these comparisons saves significant development resources and prevents costly late-stage redesigns.
Data-driven decisions
A/B testing SaaS helps companies make decisions based on facts, not just feelings or opinions. This means decisions are more likely to lead to success because they’re based on actual evidence of what works. Having real data helps companies make smarter choices that can lead to better results, like more users or higher sales. In the debate of user testing vs usability testing, A/B tests provide the quantitative "what," while qualitative sessions explain the "why," giving you a complete picture of product performance.
Continuous learning and improvement
Every A/B test teaches something, whether the test succeeds or not. This learning is very valuable as it helps build a deeper understanding of what users want. Over time, A/B testing helps SaaS teams create a habit of testing and improving within a company, encouraging everyone to always look for ways to do better. By utilizing various types of usability testing—from heatmaps to moderated sessions—teams can build a comprehensive feedback loop.
To manage this ongoing process efficiently, selecting the right usability testing tools is essential. The right platform should not only collect data but also make it easy to share these insights across the entire product team to foster that culture of continuous improvement.
How to set up an A/B test
A good A/B test follows a clear sequence, and skipping steps is where most people go wrong. Get the goal and hypothesis right at the start and the rest falls into place. Here's how to do it step by step.
- Identify a goal. It should be specific, measurable, and directly related to business outcomes, such as increasing sign-ups or user engagement.
- Formulate a test hypothesis. Predict the impact of a potential change based on existing data, user feedback, or expert evaluations. For example, hypothesizing that enlarging the ‘buy now' button will lead to more clicks.
- Create variants. Design two versions for testing – the current design (A) and the new design (B).
- Run the experiment. Use an experimentation platform like Optimizely or VWO to randomly serve either version to users.
- Analyze the results. Determine which version better achieves the set goals and gather insights to inform further decisions.
- Implement and iterate. Adopt the successful design and continue testing other elements.
Best practices for A/B testing
A/B testing is a powerful tool when used correctly. Here are some best practices to make sure you get reliable and actionable results.
Test one change at a time
When running A/B tests, it's important to change only one element at a time. This way, you can clearly see which change made the difference in user behavior. For example, if you change the color and the text of a button at the same time and see an improvement, you won't know which change was responsible for the better results. Incorporating this principle into your design QA checklist ensures that your test variables remain clean and your data stays actionable.
Test for a sufficient time period
The length of time you run your A/B test is crucial. If it's too short, you might not collect enough data to make a solid decision. On the other hand, if it's too long, it could delay other important decisions. Typically, running a test for at least one full business cycle, such as a week or a month, is recommended to account for daily or weekly variations in user behavior. This is a foundational rule of UI testing, where rushing to conclusions can lead to implementing features that don't actually perform in the long run.
Choose an appropriate sample size
You have to ensure the test has a statistical significance. The number of users you include in your test can greatly affect its reliability. Too few users and you might not get a clear picture; too many, and you might be wasting resources. Use online calculators or statistical software to help determine the ideal sample size that provides a good balance between accuracy and efficiency. This step is particularly vital to find beta testers who represent your target audience accurately enough to produce reliable metrics.
Segment your audience
Not all users are the same. Different groups may react differently to the same changes. By segmenting your audience based on demographics, behavior, or purchase history, you can understand how specific user segments respond to changes. This leads to more personalized and effective product improvements and maximizes the user testing impact in SaaS redesigns, as you can tailor the new interface to high-value power users versus casual visitors.
Collect data from every test
Documenting every A/B test in detail is essential. Record your hypothesis, the variations you tested, the results, and any conclusions or next steps. This documentation is not only useful for referring back to what’s been tested but also helps communicate the value and findings of A/B tests to other team members or stakeholders.
Account for external factors
Something outside your control can influence the outcome of your tests. Seasonal events, marketing campaigns, or changes in the competitive landscape can all impact user behavior. Account for these factors when planning your tests and analyzing the results to ensure your conclusions are accurate.
The best protection is to run both versions at the same time rather than testing A this week and B the next. That way, if a holiday rush or a sudden traffic spike happens, it affects both versions equally and your comparison stays fair.
Maintain testing integrity
Once an A/B test is live, avoid making changes to the experiment's parameters or interfering with the testing process. Any adjustments can contaminate your data, leading to unreliable results.
The hardest part is resisting the urge to peek at early numbers and call a winner before the test is done. Early results often look dramatic and then even out as more users come in, so acting too soon can send you down the wrong path. Let the test run its full course, then read the data.
Prioritize high-impact tests
Testing ideas are limitless. So, go through them and figure out which ones could have the biggest impact, are really important to your business goals, and are easy to actually implement.
A simple way to do this is to score each idea on those three points and start with the ones that rank highest. This keeps you from burning time on low-value tests and makes sure the changes you're checking are worth the wait.
Common mistakes in A/B testing
A/B testing only pays off if you can trust the results, and a few common mistakes quietly undermine that trust. The tricky part is that these errors often look like wins at first. Knowing them upfront saves you from chasing false positives.
Testing insignificant changes
Testing too minor changes, like slightly altering the shade of a button, is a common mistake. While these small tweaks can sometimes impact user behavior, they often fail to produce meaningful improvements in key metrics such as conversion rates or user engagement. It's crucial to focus on changes that have a strong hypothesis behind them, predicting a significant impact on user behavior. This is why framing your user testing questions around core functionality and user goals is more effective than focusing on purely aesthetic micro-adjustments.
Neglecting the full user experience
Focusing only on isolated parts of the user journey, such as the signup page, can lead to incomplete conclusions. For instance, while optimizing the signup process might initially increase conversions, neglecting the rest of the user experience could result in poor retention rates. Comprehensive web usability testing that considers the entire user journey from initial contact to post-purchase is essential for achieving optimal outcomes.
Not verifying test results
A frequent error in A/B testing is not verifying positive test results through replication. Teams might rush to implement changes after a single successful test without confirming if the results were consistent or just anomalies. Re-testing to confirm findings ensures that changes are genuinely effective and not just positive due to temporary conditions or external factors.Supplemental unmoderated usability testing can be a great way to quickly cross-check if the numerical "winner" of an A/B test actually aligns with how users naturally interact with the page.
Using an inappropriate sample size
Drawing conclusions from too small a sample size can lead to decisions based on statistical noise, not actual trends. Conversely, using a sample size that's too large may detect insignificant differences that, while statistically significant, don't offer practical value. Ensuring the sample size is appropriate for achieving statistical significance is key to obtaining reliable and actionable results.
Useful tools for A/B testing
You don't have to run A/B tests by hand. There are plenty of analytics tools that set up your variants, serve them to users, and crunch the statistics for you. We've grouped the most useful ones below by what they do.
Popular A/B testing tools
Here are some popular multi-purpose options:
- Optimizely offers robust features that enable enterprises to conduct extensive A/B tests and multivariate testing, providing actionable insights through an easy-to-use interface.
- VWO is a cloud-based conversion optimization platform that allows you to easily set up A/B tests, understand user behavior, and track conversion-related analytics.
- Adobe Target is a part of Adobe's marketing cloud, providing personalized and automated testing capabilities geared towards large businesses looking to scale their optimization efforts.
- Oracle Maxymiser offers a suite of tools that facilitate A/B and multivariate testing, targeting, and personalization, integrated into a comprehensive marketing hub.
- Conductrics provides a choice of interfaces, from fully automated to expert control, for conducting A/B tests and optimizing decisions across web and mobile platforms.
A/B testing calculators
Calculators specifically designed for A/B testing can help you understand the potential impact of your tests and ensure statistical rigor.
- A/B Test Calculator from CXL. This calculator helps you determine the effectiveness and significance of your A/B tests, ensuring you make decisions based on statistically reliable data.
- A/B Separation Test Significance Calculator from VWO. Use this tool to analyze the significance of your A/B tests, particularly useful for validating the distinct impact of each tested variation.
- A/B Split and Multivariate Duration Calculator Test from VWO. This calculator assists in determining the necessary duration and sample size for your tests, ensuring robust results.
- Evan Miller's Sample Size Calculator. Developed by statistician Evan Miller, this tool helps you calculate the optimal sample size needed to detect a specific effect in your A/B tests, ensuring the reliability of your results.
A/B testing statistics resources
Understanding the statistics behind A/B testing is crucial for interpreting results and making informed decisions.
- A/B Testing Statistics: An easy-to-understand guide by CXL. This guide breaks down the complex statistics of A/B testing into an easy-to-understand format, perfect for marketers and designers without a deep statistical background.
- Statistical analysis and A/B testing by DNStudio. This resource provides a deeper dive into the statistical methods used in A/B testing, helping you to better understand and apply these techniques in your tests.
- Understanding the statistics of A/B testing to get REAL Lift in conversions. This detailed guide explains how to use statistical analysis to accurately measure and understand the impact of A/B tests on conversion rates.
Final thoughts
Remember what we started with: sometimes A/B testing leads to a quicker failure? A Harvard Business School research shows that startups adopting A/B testing reach their natural endpoint faster. And that endpoint can be either scaling or falling.
And that's good. If after A/B testing it turns out that your webpage views go to zero (and that was the case sometimes) it just means that your initial idea wasn't that good. And you can move to another idea without wasting too much of your time on something that won't work anyway.
So, while conducting A/B testing is a designer's job and not founder's or product manager's on its own, you should understand that A/B testing informs business development all the steps of the way.
A/B testing is a powerful tool in the arsenal of any UI/UX designer or product manager. It helps you make decisions based on data, not just intuition, which leads to better product design and happier users.
At Eleken, we often use A/B testing on early stages of development to validate the idea or choose an option that resonates more with the users. If you are in need of a redesign or a design from scratch to validate your MVP, drop us a word!
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