A and B are well-known friends. As letters, we deal with them all life long. But they are special because they are the first we get to know at a very young age, learning the ABC and 123.

But they are not only used for building words, historically they are also used to classify, categorize, or label things, groups, or other aspects of our life and this is also the case for the topic we want to have a closer look at in this article.

Email marketing is a dynamic field, and to succeed, it is a necessity to continually adapt and enhance email campaigns. A/B testing, also known as split testing, is a powerful tool that allows to improve emails systematically. So let’s shed light on what A/B Testing is, what essential aspects are, and how to execute A/B Tests in a proper way. Furthermore, as the title of the article already implies, we will have a detailed look at how to boost open- and click rates with this strategy.

The Basics of A/B Testing

A/B testing involves creating two variations of an email—one is the control version (A), and the other is the variant (B), as simple as that.

These variations differ in one key aspect, such as the subject line, email content, images, or the call-to-action (CTA) button. A random subset of the email list is then divided into two groups, with one group receiving version A and the other version B. Comparing and analysing the results of these two different groups then helps to gauge the effectiveness of specific changes in a campaign.

A/B Testing – The General Objectives

  1. Optimized Content: A/B testing helps identify the most effective elements of emails. By testing different subject lines, content, and visuals, emails can be tailored to resonate with the audience. To optimize email campaigns for better open and click-through rates, there is the need to test and measure regularly.
  2. Personalization: Personalization is key in email marketing. A/B testing allows to personalize emails based on subscriber behavior. Test different product recommendations or content for specific segments to increase engagement.
  3. Higher Engagement: A/B testing allows us to fine-tune email content for maximum engagement, resulting in higher open and click rates. It’s essential to test and measure email campaigns regularly to ensure they are performing at their best.
  4. Conversion Boost: Ultimately, the goal of email marketing is to drive conversions. By refining emails through A/B testing, the chances increase of recipients taking the desired action, whether it’s making a purchase, signing up for a newsletter, or clicking through to your website. This can increase open rates, click-through rates, and finally conversions.

How to execute A/B Tests

The process of testing can vary depending on the email platform used and the execution might be more or less complicated but in any case, there is the following structure to be considered.

Step 1: Define Clear Goals

Before starting the A/B testing, it’s vital to establish goals for your email campaign. What’s the big dream? Whether it’s boosting open rates, click-through rates, conversions, or engagement, these goals will be your guide through the testing phase.

Step 2: Identify Testable Elements

Time to play detective! Spot the elements within your emails that deserve a dose of experimentation. Usually, the suspects are:

  • Subject Lines: Experiment with various subject line variations to determine which resonates most effectively with your audience.
  • Email Content: The meat and potatoes of your email. Mix up the elements (headlines, body text, and images) to create another version with a different “look and feel”.
  • Call-to-Action (CTA): Test different versions to find the one that attracts your audience (even) more.
  • Timing: Experiment with sending emails at different times or days and see when your audience is in the mood to follow your proposals.

Step 3: Create Diverse Variations

For each element targeted for testing, generate two or more distinct variations. Ensure that each variant varies in a single, specific aspect. For example, if subject lines are under examination, maintain consistency in email content and other elements across all variations. This approach isolates the impact of the element being tested.

Step 4: Segment the Audience

Divide your email recipient list into segments, assigning one of the variations to each segment. It is imperative to employ random sampling to guarantee that the test results hold statistical significance and are not influenced by specific audience demographics.

Step 5: Dispatch Test Emails

Distribute your test emails to the corresponding audience segments. Pay meticulous attention to details such as email delivery timing to ensure precise testing.

Step 6: Monitor and Analyze

Now watch those performance metrics like a hawk. Focus on open rates, click-through rates, and conversion rates. Employ statistical significance testing to ascertain whether the observed differences possess statistical validity.

Step 7: Determine the Superior Variation

Identify the variation that surpasses the others in alignment with your predefined objectives. This variant becomes the “winning” one.

Step 8: Apply the Successful Elements

Incorporate the successful elements derived from your A/B test into forthcoming email campaigns. This might entail integrating the best-performing subject lines, email content, or CTAs.

Step 9: Sustain Ongoing Testing

Email marketing is a never-ending story. Keep experimenting with different elements and fine-tuning your campaigns to remain competitive and to keep your audience entertained.

Dedicated Tips for Improving Open Rates:

  1. Subject Line Testing: Test variations in length, tone, and urgency to see which drives higher open rates. For example, you can test a short and intriguing subject line against a longer, more descriptive one to see which performs better.
  2. Personalization: Personalized emails tend to stand out in crowded inboxes. A/B test personalized content, including the recipient’s name or tailored recommendations. Assess whether personalized emails result in higher open rates compared to generic ones.
  3. Timing Matters: The timing of your email sends can significantly impact open rates. A/B test different sending times and days to determine when your audience is most responsive. For instance, you might find that sending emails on Tuesday mornings generates better open rates than Friday afternoons.
  4. Segmentation: Segmenting your email list based on demographics, behavior, or preferences can improve open rates. A/B test content variations for different segments to determine which messaging resonates best with each group.

Tips for Improving Click Rates:

  1. CTA Testing: The call-to-action (CTA) is a critical element for click rates. A/B test your CTAs to find out which wording, color, size, or placement encourages more clicks. For example, test “Buy Now” against “Shop Now” or “Click Here.”
  2. Email Content: Experiment with the content within your emails. Test different headlines, body text, and images to identify what resonates best with your audience. For instance, you can test an image-heavy email against a text-focused one to see which generates more clicks.
  3. Segmentation: Just as with open rates, segmentation plays a role in click rates. Segment your email list and tailor content to specific segments. A/B test content variations for different segments to boost click rates. For example, test a product-focused message with a segment interested in that product category.
  4. Mobile Optimization: Since a significant percentage of emails are opened on mobile devices, it is essential to ensure that your emails are optimised for this type of display. In case you are undecided about the time investment required to adapt designs to the needs of mobile devices, an A/B test can be very useful. It will allow you to assess whether emails with mobile-responsive designs generate higher click-through rates than non-responsive ones, giving you concrete data to make an informed decision.
  5. Clear and Compelling CTAs: Make sure your CTAs are clear and compelling. A/B test different CTA copy and design to determine which ones result in more clicks. For instance, test a direct CTA like “Get Started” against a more descriptive one like “Start Your Free Trial.”


A/B testing is a powerful method for iterating and improving your email marketing efforts. By systematically testing and refining different elements, you can optimize your emails for better engagement, higher conversion rates, and ultimately, more successful email campaigns.

Always remember to set clear goals, test one element at a time, and apply the insights gained to continually enhance your email marketing strategy. In this ever-evolving landscape, A/B testing will definitely be your new friend.