Successful Email Campaigns Thanks To A/B Testing

Email campaigns can be optimized in many ways. Running A/B tests is one of the most popular and effective methods. But what exactly are A/B tests? How do you do it? With this article you will learn the most important things about testing.

Written by Hannah Krüger

Small Change, Big Success

 Your newsletter is created. The designs, content and subject lines are in place. But although everything seems perfect, your email is hardly opened? And the click-through rate is below your expectations? Thanks to A/B testing, your newsletter is transformed step by step into a perfect campaign with top performance. 

What Is A/B Testing?

A/B testing (also split testing) is a method from online marketing. The goal of an A/B test is to find out which content, design or wording your users find most appealing. 

This involves comparing two or more versions of an email, landing page or advertisement in terms of performance. 


The versions (version A and version B) are sent to different recipients. At the end of the test phase, it is determined which version performs best. The winning version is sent to the remaining subscribers. 

A/B tests can be used, for example, to optimize newsletters in terms of their open and click rates. 

Which Elements Should I Test?

Any design and text-related elements can be tested. Within A/B testing, a distinction is made between simple and complex comparisons. In a simple comparison, a maximum of two customizable elements are tested against each other. In complex, multivariate tests, several elements are examined, such as entire templates. 


Basically, the following elements can be tested in email marketing: 


Subject Line & Preheader

The subject line and the preheader are the first things your recipients see in the inbox. No matter how exciting you build your newsletter, if the preview in the inbox is not convincing, your email will not be opened and read. Therefore, subject line and preheader are incredibly important to the success of a campaign. 

Test the following variations: 


  • Play with the text length 
  • Try out formulations such as questions or assertions 
  • personalized address
  • Use emojis




When your email is opened, the choice of images is crucial. Your users process images many times faster than text. That's why images, GIFs, and videos are seen first. If the visual is convincing, it is more likely that their content will be read further. 

Test the following variations: 


  • Banner
  • Product images
  • Videos
  • GIFs
  • Different sizes & placements 
  • Image or no image?



It's not just the layout and design of your email that matters. The content of your campaign is also important. Only coherent and exciting content is convincing. Make sure that you don't digress when texting and always focus on the most important message.

Test the following variations: 


  • Text length 
  • Wording 
  • Placements 




If images, subject lines and texts are convincing, the only thing missing is the click on the Call-To-Action button (CTA). CTAs allow users to complete your defined call-to-action. CTA buttons represent the goal of your email campaign: to convince the subscriber of a product or offer so that they visit your website. This ultimately leads to more leads on your website.


Test the following variations:  


  • Colors 
  • Sizes
  • Styles like frames or rounded corners 
  • Wording 


Sending Time 


In addition to content and design, different dispatch times can be tested. Simply send the same newsletter to different groups of recipients at different times. In this way, you can find out whether your subscribers prefer to read your e-mails in the morning or in the evening. 


Test the following variations:


  • Times 
  • Weekdays & weekends


Our Tips For Effective A/B Testing

Determine Target 


Before you immediately start A/B testing, take it easy. Take a look at your last few campaigns. What went well? Where is there still potential for improvement? What rate are you dissatisfied with? 


Set yourself a specific goal that you would like to achieve. Do you want to increase the open rate? Test different subject lines, preheaders and send times. Your click-through rate is too low? Play with images, texts, and buttons as well as placements and design. 

Run Multiple Tests 


We recommend testing a maximum of two elements per A/B test. If you test countless changes at once, you won't be able to judge afterwards which element contributed to success or failure. So remember: the fewer elements you test, the clearer the result will be. So test all the elements one by one. 


After the test is before the test. Have you finally found the right wording for the subject line? Great! Now move on to the next element. Repeat the A/B tests until you have tested every element.


    Examples For A/B Testings

    Improve Open Rate 


    • Subject line: creative vs. factual 
    • Subject line: with emojis vs. without emojis
    • Address: personalized vs. impersonal
    • Sender data: Employee name vs. generic name 

    Improve Click-through Rate & Conversions


    • Content: casual vs. businesslike tone 
    • Address: you vs. you
    • Text link vs. button 
    • Visuals: images vs. videos 
    • Design: colors & styles 
    • Length of the newsletter


    Easy Going With JUNE 

    Before sending an email, you can add another version with just one click. Both versions are sent to randomly selected groups of recipients. You can select the percentage of the respective recipient group. After the end of the test phase, we analyze the results for you. The clear winner will be highlighted and sent to the remaining subscribers. 



    With the help of A/B testing, you will find out after a while what appeals most to your target audience. So test the visual design and the content. After a while, you'll get a sense of which elements resonate best. Thus, creating campaigns will be easier than before. Another plus: attractive newsletters also improve your KPIs: open, click and conversion rates increase. This results in more leads and more sales on your website.


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