Email A/B Testing: What You Can (and Should) Test
A/B testing is your secret weapon when it comes to optimizing your marketing emails.
Email A/B testing, also known as split testing, involves taking two variants of some component and seeing which one performs better. This is done by splitting an email list into two groups at random and showing a different variant to each group. You can then look at metrics like open rate, click-through rate, and website conversions to evaluate which email version performed better.
It doesn’t take a lot of technical know-how to get started with split testing. In fact, A/B testing tools are built into most major email marketing platforms, including:
- MailChimp
- Pardot
- Constant Contact
- Campaign Monitor
- HubSpot Email
Why Should Email Testing Be Part of Your Marketing Strategy?
Email testing gives you real feedback from the audience that matters to you most: your current (or potential future) customers. With email A/B testing, you can answer questions like: Are my subscribers more likely to open my emails in the morning or evening? Do subscribers prefer a more formal or casual tone? and What promotional offer most appeals to my customer base? Once you have answers to those questions, you can optimize your emails to increase the number of recipients who open your message, click a link to your site, and ultimately convert.
A Few Email Testing Best Practices
While it can be tempting to jump right in and test as many email components as possible, it’s best to only test one variable at a time. That way, you’ll be able to pinpoint what recipients are responding to, rather than trying to guess what combination of five changes increased your click-through rate.
In most cases, you’ll want to start by running an A/B test with a small percentage of your list, and then send the winning email version to your whole list. (Most email marketing platforms will let you do this easily.)
However, there’s also an argument to be made for running an A/B test with your whole list, because you’ll have a larger sample size (and stronger test results). This type of large-scale test is best to run if you’re planning to change something across multiple emails, such as the layout of your weekly newsletter or the button on your monthly discount offer.
9 Email A/B Tests to Try
Time of Send
We can’t tell you the best day of the week or time of day to send your emails because there’s so much variation by industry. The only way to find out is through email A/B testing. The results may surprise you. For instance, as a B2B marketer, you might think that 8 am is the best time to send emails because business buyers are arriving at the office and checking their email, but after testing your hypothesis, you might find you get a higher response rate when you send in the late afternoon.
Subject Line
If your open rates are low, you may want to start by A/B testing your email subject lines. Here are a few ideas for email subject tests you could run:
- Shorter vs. longer
- Different tones (e.g. funny vs. urgent)
- Including the recipient’s name or leaving it out
- Making the focus of the email clear or playing on the reader’s curiosity
- Including emojis or not
Just remember that it’s an email testing best practice to only evaluate one variable at a time.
From Name
The From name is another good variable to test if you’re trying to improve your open rates. Try running a test where half your list gets an email with your company’s name as the From name and the other half gets an email from an individual at your company.
Call to Action

Example of a CTA button in an email from Bed, Bath & Beyond
Maybe you’ve been seeing decent open rates but unusually low click-through rates. In this case, you might want to test your call to action (CTA). You could test:
- The wording of the CTA (e.g. “Buy It Here” vs. “Shop Now”)
- Placing the CTA in a button vs. a text link
- The placement of the CTA button in the email
- The color of the CTA button
Length of Email Message
Depending on your audience and offer, you might get a higher click-through rate if you keep your email message short and sweet or go longer and provide more information. Leverage ran this test on one of our recent email campaigns and found that with our audience, the short messages got a higher response rate. However, there’s no guarantee your business will get the same result, and you won’t know until you test.
Layout
Your text isn’t the only thing you can test—you can also use email testing to optimize your design. For example, you might try split testing a single column vs. double column layout, or more vs. less white space. And considering that 66% of emails are now opened on mobile devices, you should definitely test elements that will affect how readers interact with your emails on a small screen.
The Specific Offer
Find out what best motivates readers to click through to your site by testing different email offers. You could, for example, evaluate whether you get more clicks (and conversions) when you offer readers a mystery gift with their next purchase vs. 25% off their next purchase.
Images
Images can be a great way to entice email recipients to click through to your site, especially if you have visually appealing products. Visual variables you could test include:
- The size of your images
- The number of images
- Your color palette (e.g. brighter vs. darker)
- Photos vs. illustrations
Just keep in mind that not every email recipient will be able to see your images, and run emails that will be cohesive whether the images show or not.
Other In-Email Elements
We’ve barely scratched the surface when it comes to email A/B testing. There are many other variables you could test, including elements like videos, animations, and testimonials.
Whatever you decide to test, pay close attention to the metrics that tie into your business goals. Increasing your open and click-through rates is great if you’re running an awareness campaign, but if you’re trying to increase sales or sign-ups, you should be paying attention to the percentage of recipients who complete a conversion after clicking your email.
Coming up with an email marketing testing strategy may seem daunting, but it’s a lot easier when you have an experienced digital marketing team in your corner. Contact Leverage today to learn more about our email marketing services.
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