Definition of Email A/B Testing

Email A/B testing is a digital marketing strategy that involves sending two different versions of an email campaign to a small percentage of a target audience to determine which one performs better. The variations may include changes in subject lines, email content, layouts, or call-to-action buttons. Based on the results, the better-performing version is then sent to the rest of the subscribers, optimizing open rates, click-through rates, and conversions.


The phonetic pronunciation of the keyword “Email A/B Testing” is:E-mail: /ˈiːmeɪl/A/B: /ˈeɪˈbiː/Testing: /ˈtɛstɪŋ/You would say it as: “ee-mayl ay-bee testing.”

Key Takeaways

  1. Helps to optimize and improve email marketing campaigns by testing different variables.
  2. Increases open rates, click-through rates and conversions by identifying elements that resonate with the audience.
  3. Continual and consistent testing enables data-driven decision-making for improved overall email performance.

Importance of Email A/B Testing

Email A/B testing is important in digital marketing as it allows marketers to optimize their email campaigns by comparing the effectiveness of two different versions of an email.

This process helps in identifying which element, such as subject lines, call-to-action, design, or content, resonates better with the target audience and results in higher open rates, click-through rates, and conversions.

By continually measuring and analyzing the performance of email variations, marketers can make data-driven decisions to enhance their email marketing strategies and achieve better engagement, thus maximizing the return on investment from their email campaigns.


Email A/B testing is a crucial element in digital marketing campaigns as it serves the purpose of optimizing email performance and ensuring that the messages sent to the target audience are effective in achieving the desired results. It enables marketers to experiment with various versions of an email, comparing differences in subject lines, designs, content, call-to-action buttons, and other elements in order to determine which version resonates best with their audience.

By analyzing the engagement and click-through rates, as well as conversion metrics for each version, marketers can identify the attributes that are most successful in driving desired outcomes and apply these insights to future campaigns. The ultimate goal of email A/B testing is to constantly improve the effectiveness and return on investment (ROI) of email marketing efforts.

By leveraging data-driven insights and continually refining email strategies, marketers are better equipped to tailor content and messaging to the preferences and needs of their target audience. This enables more efficient spending on marketing initiatives, as generating higher conversion rates can lead to increased revenue and stronger customer relationships.

Additionally, insights gained from A/B testing can also be applied to other aspects of digital marketing, such as website design or social media campaigns, which can in turn support the overall success of a company’s marketing efforts.

Examples of Email A/B Testing

Subject Line Testing: An online fitness store wants to increase its newsletter open rates. The marketing team decides to run an A/B test on the email subject lines to determine which version will perform better. They create two different subject lines: one focused on promoting a discount (subject A: “Get 20% off on our bestselling workout gear!”) and another focused on emphasizing the quality of their products (subject B: “Upgrade your fitness game with our high-quality gear!”). The emails, identical in content, are sent to two equal-sized random groups of newsletter subscribers. After monitoring the open rates for a week, the marketing team analyzes the results to see which subject line led to a higher engagement and applies that insight to future campaigns.

Call-to-Action (CTA) Testing: A software company wants to increase the number of users signing up for its product’s free trial. To do this, they run an A/B test on the CTA buttons included in their promotional emails. The first version (A) has a CTA saying “Start Your Free Trial Now”, while the second version (B) uses the text “Discover the Benefits with a Free Trial”. The company sends both versions to random, equal-sized segments of their email list. After evaluating the click-through rates and subsequent trial sign-ups for each group, the company determines which CTA generated more conversions and implements it for their upcoming email campaign.

Email Design and Layout Testing: An e-commerce fashion brand wants to optimize its promotional emails to boost click-through rates and ultimately increase sales. They create two different email layouts to test: the first one (A) has a more text-heavy design with product descriptions, and the second one (B) focuses on large, visually appealing images of their products. They send out both versions of the email to separate yet equally-sized groups of subscribers from their mailing list. After tracking click-through rates, conversion rates, and purchase data for both groups, the marketing team decides which layout performed better and adopts it as their new email design template.

Email A/B Testing FAQ

What is Email A/B Testing?

Email A/B Testing, also known as split testing, is the process of systematically comparing two or more versions of an email to determine which version performs better. This helps to optimize your email campaigns for better engagement and conversions.

What elements can you test in an Email A/B Test?

You can test various elements in an email, such as email subject lines, preview text, headlines, images, call-to-action (CTA) buttons, layout, and content. Split testing these elements can help you understand what resonates best with your audience.

How does Email A/B Testing work?

Email A/B Testing works by sending out different versions of an email to smaller, random segments of your subscriber list. Once you gather the necessary data, you compare the performance indicators like open rates, click-through rates, and conversion rates to determine the winning version. Based on the results, you can make data-driven decisions to improve your overall email strategy.

What are the benefits of Email A/B Testing?

Email A/B Testing benefits include improved open rates, click-through rates, and conversion rates, higher engagement, a better understanding of audience preferences, and the ability to optimize email campaigns continuously.

How long should you run an Email A/B Test?

The duration of an Email A/B Test depends on your email frequency and the size of your subscriber list. Generally, it’s recommended to run the test for at least one to two weeks to gather enough data, but the optimal duration may vary based on your specific needs and goals.

Related Digital Marketing Terms

  • Open Rate
  • Click-Through Rate
  • Subject Line Variations
  • Call to Action
  • Conversion Rate Optimization

Sources for More Information

Reviewed by digital marketing experts

More terms

Guides, Tips, and More