A/B testing
A/B testing, also called split testing, means running two versions of a page, email or ad side by side to see which performs better. Half of your visitors see version A, the other half version B, and the numbers pick the winner. Here you'll read how to set up a good test and which mistakes to avoid.
- 6 min read
What is A/B testing?
A/B testing, also known as split testing, is actually a very simple concept. You take an element of your website or marketing campaign, make two versions of it (let’s call them A and B), and show them to different groups of users. Then you look at which version performs better based on the goals you set, for example more clicks on a button or more sign-ups for a newsletter.
Why would you A/B test?
The great thing about A/B testing is that it lets you back up with hard numbers what does and doesn’t work. Instead of guessing whether a certain change is better, testing lets you see which version actually delivers the best result. This leads not only to higher conversions, but also to a better user experience and more satisfied visitors.
How does A/B testing work?
Step 1: Define your goal
Before you start, you need to be clear about what you want to achieve. Do you want more people to sign up for your newsletter? Or do you want visitors to stay on your website longer? This goal is your compass during the test.
Step 2: Choose what to test
Now that you know what you want to achieve, you can decide which parts of your website or campaign you want to test. This can be anything, such as:
- Headlines: What appeals more to your target audience?
- Call-to-action (CTA): Which button draws more clicks?
- Images: Which image attracts more attention?
Step 3: Create your variants
Now comes the creative part. You make two versions of the element you want to test. Make sure you change only one thing at a time, so you know exactly what made the difference. So for example: in version A you use a red button, in version B a green button.
Step 4: Start the test
The next step is to put your test live. Split your visitors randomly between version A and version B. This often happens automatically through special software, so you don’t need to worry about it. It is important, though, that your test runs long enough to get reliable results. A few days can be enough, but sometimes a longer period is needed.
Step 5: Analyse the results
When the test is over, you look at the results. Which version performed best? Maybe the red button got more clicks than the green one. This is valuable information you can use to improve your website or campaign straight away.
Step 6: Implement the winning variant
Got a clear winner? Congratulations! You can now roll the winning variant out on your website. Don’t forget to keep monitoring your performance after the change. The digital world moves fast, so what works today doesn’t always work tomorrow.
What can you test with A/B testing?
The great thing about A/B testing is that you can test almost anything. Here are a few ideas to get you started:
1. Headlines and subheadings
The title of a page is often the first thing someone sees. A strong headline can make the difference between a visitor who reads on and one who leaves straight away. Try different styles, lengths and words to see what works best.
2. Call-to-action buttons
CTA buttons are the direct gateway to Conversion. By testing the colour, size, text or placement of your CTA button, you can find out what motivates people to click.
3. Layout and design
The layout of your page shapes how visitors experience your content. Test different page layouts, the use of white space, and the placement of key elements such as forms and buttons.
4. Images and videos
Visual content is often a major factor in how people experience your website. Try different images or videos to see which work best.
5. Forms
Forms are often a bottleneck in the conversion process. Test the number of fields, the order of the questions and the labels to see how you can get more people to convert.
Benefits of A/B testing
A/B testing offers plenty of benefits, whether you’re a small business owner or run a large company:
1. Higher conversions
The main benefit of A/B testing is that it increases the chance of conversion. By improving step by step, you can raise the effectiveness of your website or campaigns considerably.
2. Better ROI
A/B testing helps you use your resources more effectively. By investing in what works, you get more return from your marketing budget.
3. Insight into your visitors
A/B testing shows you what your visitors really value. You can use that knowledge not only to improve your current website, but also to shape future strategies.
4. Less risk
Big changes can be risky. With A/B testing you can run small, controlled experiments, which minimises the risk of a negative impact.
Common mistakes in A/B testing
Although A/B testing has many benefits, there are also a few pitfalls to watch out for:
1. Testing without a clear goal
Without a clear goal, it’s hard to tell whether your test was a success. So always make sure you know what you want to achieve before you start.
2. Testing too many variables at once
If you change several things at once, you won’t know exactly what influenced the results. So test one thing at a time.
3. Testing with too small a sample
If you include too few visitors in your test, the results can be unreliable. Make sure your sample is large enough for statistically significant results.
4. Testing for too short a time
A test that runs for too short a time can lead to skewed results. It’s important to let your test run long enough to gain genuinely useful insights.
When should you use A/B testing?
A/B testing is useful pretty much any time, but there are specific situations where it’s truly indispensable:
1. For new launches
When you launch a new website or campaign, you want to know quickly what works and what doesn’t. A/B testing helps you make optimisations from day one.
2. For optimising existing pages
Seeing that certain pages perform less well? With A/B testing you can find out exactly what needs improving.
3. Regular updates and maintenance
Your visitors’ preferences can change over time. By testing regularly, you make sure you always stay ahead.
Tools for A/B testing
To run A/B tests properly, you need the right tools. Fortunately, there are plenty of good options:
1. Optimizely
Optimizely is one of the most popular platforms for A/B testing. It’s somewhat more extensive and also offers features such as multivariate tests.
2. VWO (Visual Website Optimizer)
VWO is user-friendly and, besides A/B testing, offers extra tools such as heatmaps and click maps to help you better understand your visitors’ behaviour.
Conclusion
A/B testing is a handy way to optimise your website and marketing campaigns. It lets you make decisions based on data, which leads to higher conversions, a better user experience and, ultimately, more success for your business. Whether you’re just starting out or have been at it for years, A/B testing lets you keep improving.
Start A/B testing today and see for yourself how small changes can make a big difference!
Would rather not work this out yourself? We set up A/B testing as a standard part of conversion optimisation, including the statistics that determine when a test is finished. You can read more at above the fold, Analytics and ROAS.
Frequently asked questions
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Hoe lang moet een A/B-test lopen?
Een A/B-test loopt tot je genoeg bezoekers en conversies hebt voor een betrouwbare uitkomst. Soms is dat binnen een paar dagen, vaak is een langere periode nodig. Stop een test niet zodra één versie voorloopt, want te kort testen geeft vertekende resultaten.
Wat is het verschil tussen A/B-testen en multivariate testen?
Bij A/B-testen vergelijk je twee versies waarin één element verschilt. Bij multivariate testen verander je meerdere elementen tegelijk en meet je welke combinatie het beste werkt. Multivariate testen vraagt veel meer verkeer, daarom is een A/B-test voor de meeste websites de logische start.
Is A/B-testen zinvol voor een website met weinig bezoekers?
Beperkt. Met weinig verkeer duurt het lang voordat een test een betrouwbare winnaar aanwijst. Begin dan met grotere verbeteringen op basis van gebruikersgedrag en test pas als het verkeer groeit. Hoe wij dat aanpakken lees je bij A/B testing.
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