How to Get Started with Email A/B Testing


As an email marketer, you know how important it is to optimize your email campaign for better performance. One of the fundamental ways to do this is by a/b testing your emails. According to research conducted by Litmus, businesses that a/b test every email see 37% higher ROI than those that never include a/b tests.

This guide will show you what email a/b testing is, how it works, and the benefits it provides. Additionally, we will give you the best practices to follow while conducting a/b testing.

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What is email a/b testing?

A/b testing or split testing in email marketing is a trial run in which you test different variations of a similar email campaign. Then, you send these email variations to two different segments of your audience.

The purpose of a/b testing email is to figure out which email variant generates the best results and improves your email metrics. The version that shows positive metrics such as improved open rates and conversion rates is termed a “winner.”

In simple terms, think about the experiment you did in school when you put two unripe bananas in two different packaging - one in a paper bag, the other in a plastic bag. The result would be different for both the packaging. In the same way, a/b testing your emails can help you identify which version is generating better results.

Why should you a/b test your emails?

It is challenging to guess what is working and what is not. And if you guess wrong, it could be a waste of your time and resources. So here’s where a/b testing comes into play.

A/b testing helps you build data-backed decisions to achieve your goals and can benefit your email marketing campaign in the following manner:

Increase open and click-through rates

A/b testing different subject lines can help you identify which subject line resonated most with your audience. For instance, you might find that a personalized subject line prompts more users to open their emails. Then you can use this tactic to increase your open and click-through rates.

Cost and time effective

A considerable amount of money and time is invested in creating the email design and layout, subject lines, sending those emails to a broad audience, and much more. Being oblivious to which element isn’t working can lead to needless expenditure.

A/b testing 2 or 3 elements can help you determine which feature provides a more engaging user experience. Then, you can implement those changes, get statistically higher returns on your investment, and save time.

How to decide what elements to a/b test?

Steps to decide what elements to A/B test

Follow these steps to decide what to a/b test:

Collect data and identify the problem

The first thing you need to do is collect data using email analytics. Then, look at various metrics and figure out which metric is not performing well.

Define your goals

Now, decide which metric you want to improve. Make sure your goals are clear, measurable, and achievable.

Formulate hypothesis

Hypotheses are the assumptions made based on datasets to prove how a particular variation might perform better than the other. Keep your goals in mind while you are formulating your hypothesis.

For example, if you come up with multiple hypotheses, prioritize them based on whichever seems more relevant to you.

This table summarizes the different elements of your email you can test:

Data collection and problem identificationGoalsWhat to test (Hypothesis)
Email open rate is lowImprove open ratesEmail subject line and pre-header text
CTOR is lowBoost Click-through ratesContent of your email and the layout and design of your emails
CTOR and conversion is lowBoost conversions and ROICall-to-action

How to perform a/b testing on your emails

How to perform a/b test on your emails

After developing your hypothesis, you can start testing your email in the following manner:

Create variations of your email

Make variations in different elements of your email, which you will test. For example - you can create two personalized subject lines or use a button as CTA rather than a text. Doing so will help you figure out which version seems more engaging to your audience.

Run a/b tests

Now that your email variations are ready, it’s time to run the test. Kick off your trial run by sending one version to a subset of the audience and the other to a different subset. Monitor the interaction of your audience, and collect data using different metrics.

Analyze the results

Then, compare the result of both versions and identify a champion version. You can now use this champion version to garner good returns by sending it to different segments of users.

If the results you get through the variant version are not good, try testing with a different element. This a/b test process can continue until you get the desired result.

How long should your email a/b tests run?

A question that might arise while a/b testing is how long you should run your tests? Well, there is no definitive answer to this question. A lot of factors contribute while deciding the duration of your a/b testing. Some of them include - your business goals, audience size, metrics you want to test, email marketing budget, etc.

A survey conducted by Mailchimp reflects the estimated time it took to generate results depending on the metrics. A winner was selected in 2 hours for the open rate in 80% of the cases. At the same time, they chose a champion version for the Click rate in just 1-hour. In the case of revenue generation, it took 12 hours to find a champion version successfully.

So, it is pretty clear that there is no pre-defined time frame for running your testing. However, letting your tests run for adequate time will give you more confidence while deciding the champion version of your email.

Email a/b testing best practices

Much of your organization’s success depends on how you carry out email a/b testing and draw insights from data to increase conversions. That is why you must follow the correct practices.

Here are two of the most important practice that many email marketers forget to follow:

Test emails simultaneously - Timing of your email testing matters. There are chances that if you run your testing at different times, you may get skewed results. Thus, it is crucial to simultaneously carry out an email a/b test to get optimum results.

Use a representative sample size of your subscribers - It is imperative to choose a suitable set of audiences having similar interests, behaviors, locations, etc. Testing your email by sending them to the wrong audience may not yield the desired results.

Start a/b testing your emails today

Now, it's time to put a/b testing into practice. First, look at your email analytics and figure out what you want to test in your email. And then choose tools that provide you affordability, insightful data, as well as the flexibility to experiment with variables.

With Mailmodo, you will be able to alter and send interactive variations of your emails. This, in turn, will help you generate higher ROI from your email campaigns. Additionally, when you sign up with Mailmodo, you get a free trial with unlimited credits. You can read this if you want some email testing tools.

So, what are you waiting for? Start email a/b testing today with Mailmodo.

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