Talk with a deliverability expert

No need to flee, it's totally free

All about A/B testing in email marketing, with Examples and Tips
Inna Sabada
by Inna Sabada
All about A/B testing in email marketing, with Examples and Tips

Mastering A/B Testing in Email Marketing: An In-depth Exploration with Practical Examples and Proven Tips for Success


“A mistake that some companies make is to start moving a bunch of levers around without clear planning upfront for what they're trying to optimize—and what will be impacted by those changes.”
― Dan Siroker, A/B Testing: The Most Powerful Way to Turn Clicks Into Customers



1. What is A/B email testing and its role in email marketing


Email A/B testing is a way to measure the effectiveness of your emails through experiments. In A/B testing newsletter, you create two versions of an email to see which one is better. Part of the audience will receive the first letter, and part - the second. Next, look at the results of your newsletter, pay attention to:

- deliverability;
- open rate;
- clicks on links;
- the number of unsubscribed subscribers.

And choose a more effective email option.



There is also an option to send Version A to 10% of your customer base, Version B to another 10%, and the winning campaign will be sent to the other 80% of your base. Such opportunities are provided by marketing automation tools.



2.  What is A/B testing email for?


✅ This is the fastest way to increase efficiency and revenue from newsletters. Such testing helps to quickly test hypotheses.


✅ Testing helps you quickly make the right decisions, which are not based on intuition but based on specific numbers.


✅ A/B testing newsletter can help you better understand your target audience in the end. Their needs, desires, what content works best, etc.


✅ With the help of testing, you can minimize risks and financial losses.


✅ Determine what problems arise when launching email marketing campaigns.


✅ Improve the reputation of your domain. If your emails open better and your audience interacts with them more, your domain's reputation in the eyes of email services will grow.



3. Types of Email A/B testing:


1. Simple. In this option, the email changes minimally. For example, only the subject line or call to action changes.


2. Complicated. In this case, the email options are very different from each other. For example, the content of the letter or the entire design template, links, and buttons change. With the help of such a test, it is checked which version of the email will bring more targeted actions.



4. Rules for A/B email testing.


Here are the basic rules:


1. The most important thing is to test only 1 element at a time!


2. Make sure you're doing everything right to ensure email delivery. There will be nothing to test if the letters do not reach the recipients. The email needs to be warmed up before sending. Use our tool for this - Warmy 


3. When testing, send emails to the same audience segment.


4. The larger the audience of your subscribers, the more significant your data will be.


5. Plan to test your content ahead of time to allow time for the team to work on it.



5. The subject of Email A/B testing



1. Subject and preheader.

2. Sender name. 

3. Email format - text or HTML.

4. Email content.

5. Links.

6. Call to action - one or more.

7. Sending time.



1. Subject length, email.
2. Color of buttons and links.
3. Presence or absence of prices.
4. Tone in emails.

Let's consider each in more detail.


5.1 Email Subject


A good subject line can increase your open rate by 15% or even 30%. Its role is difficult to overestimate. It is important here to grab the attention of the recipient among the mass of screaming “Open Me” headlines. Something superficial and barely perceptible is not suitable for the subject of the letter. To attract attention, the subject line must have a strong reason to open this particular email.


In the subject line of the email, you can change:

✔ Personalization. You can compare whether the general subject of the email works better or the name of the person in it. You can also write the name of the company or the position of the person.

✔ Use questions in the email subject. Creating some intrigue.

✔ Using numbers, percentages, etc.

✔ Emoji in the email subject. They help increase the open rate.


5.2 Preheader


Since we most often read mailings from mobile devices, the preheader becomes a very important element. In our inbox, it appears right after the subject of the letter - as if the second subject. It has 2 main purposes.


1. It can enhance the effect of the subject line by revealing it.

2. It can serve as an additional reason to open the letter.


If there are several topics or names in the email, mentioning two at once with the help of a subject and a preheader will attract more interest (hence, the open rate will be higher).


5.3 Sender name


Slight adjustments to the sender's name (but not the address) can make a big difference. This is your standard name, brand name. At the same time, testing helps to determine which name has the best effect on open rates. It is important to consider that it does not mislead recipients.


See what works best:

☑ the name of the employee;
☑ position of the employee;
☑ employee name + position;
☑ company name;
☑ employee name + company name;


5.4 Email format - text or HTML


Your email can be sent as a plain text email or a beautiful HTML email. For example, you can use the built-in email templates if you are using any tool to send email. Buttons with links, your logo, background colors, etc. can be inserted into the template.


5.5 Email content


What can be tested:

1. Use of text, image, or video.
2. Email header font and size. To make the newsletter look readable and legible, use no more than three fonts in one letter.
3. Text layout: one column, two or better three.
4. Colors of text, headings.
5. Using a list for text. As a rule, the list is much more convenient and pleasant to read than solid text.


5.6 Links


You can test the number of links. One or more. As a rule, we advise you to use no more than one link, because if there are many links in the letter, it may end up in the spam folder. Especially if your domain is new and your mailing list is very large.


Read also - "Complete guide - how to send bulk emails without spamming"


Also, test the link format. It can be text+link, or a link within the text, or a link within a button.


5.7 Call to action - one or more


A very important element on which your success depends.

The first rule, the call to action must be mandatory! Then you can experiment with the number of calls to action, where to place them, at the beginning of the letter or the end. You can also place a call to action inside a button.


If you want to learn more about the rules for writing calls to action, read our article - Call to action. Rules.


5.8 Sending time


The ideal dispatch time is a very complex issue. It depends on so many factors, so you need to study your audience and only by experimenting to understand when exactly your audience is most responsive.


Segmentation of your audience will help in this matter.


✔ Emails sent on Tuesday, Wednesday and Thursday show the best results. This applies to both B2C and B2B.


✔ Don't forget about time zones. If your subscriber base consists of people from different countries, be sure to take this into account. Send the letter so that it arrives at a convenient time for subscribers. It is very convenient to use the schedule, where you can set the exact time for sending your email.


✔ Tuesday, Wednesday, and Thursday are the best days to send emails.


✔ Business emails are best sent during business hours. Approximately from 11:00 to 16:00


✔ Entertaining or educational content and advertising - after 18:00


✔ Late evening and night emails are read by young people aged 20 and over, while retirees prefer to open emails in the morning.


These were the main elements for testing. In fact, there are more than enough of them, but if you want to become an email marketing guru, here are some more elements that you can test to improve your results.


5.9 Subject length, email


Email subject length. Just try different options, but do not forget that too large an email subject line will be hidden by the screen.


Content length.  Don't write too long letters, no one likes to read long, be brief, and make do with a call to action or a picture.


5.10 Color of buttons and links


Button design and colors are also important. Some colors have been proven to have a special effect on people. It is best to stick to brand colors.


5.11 Presence or absence of prices


Experiment with prices. Try email options with or without pricing.


If you currently have discounts, this is a good reason to use them in your letter.


A / B testing will tell you how to better visualize prices, attract the attention of the audience and increase CTR.


5.12 The tone of your emails


In emails, the tone is the attitude you want to convey to the recipient. The tone of your email can express a variety of moods, such as professionalism, friendliness, or optimism. If you can't decide how to address the subscriber with "you" or "you", use a formal or more informal tone, try it. What works best for your audience will be determined through A/B email marketing testing.


A/B email marketing testing is a great way to optimize your email messages, as there is no one right email style.


Don't guess - check!