How to A/B Test Email Marketing Campaigns for Better Results?

Email A/B testing — Gmail Window
Photo by Sigmund on Unsplash
  • What can you test?
  • How to A/B test your emails?
  • What are some of the best practices you can follow?

What is A/B testing & Why you need it?

In the world of email marketing, A/B testing (also known as split testing) is when you create and send two variations of the same email campaign to two or more subsets of your audience and based on the responses, decided which one is more effective.

A/B testing example 01-Obama/Biden

What can you test?

A/B testing is useful for testing a number of elements in your email campaign. The most common elements you can test are:

Subject lines

One of the most visible components of your campaign is the subject line. Most devices format subject lines with darker, heavier text so they stand out among other parts of the email.

A/B testing subject length example 02-Topshop


Images help convey what even a thousand words won’t be able to. At the same time, they can also be distracting. If you want users to focus on your design without having to read much, images are a great help. On the other hand, if you want users to focus on your content, images can be distracting.

A/B testing image use example 03-SitePoint


Users love a personalized message. Studies have shown that personalizing an email campaign can boost click-through rates by up to 14%.

A/B testing personalization example 04-DropBox

Choice of words

Words are free, it’s how you use them that defines whether they’ll help you or cost you. This includes the order of words, tone, and even quantity of content used.

  • Get up to 25% off your next purchase at Walmart

Call to action (CTA)

Your email marketing campaigns need an effective call to action to be successful. CTAs increase the click-through rate of your emails by clearly communicating to readers what the next steps are.

A/B testing CTA example 05-Sephora
  • Button content


There are many numerous types of visual layouts and designs you can use in your email campaigns.

A/B testing layout example 06- Freshbooks-SmugMug
  • Visual and graphics: Some users prefer visuals to explain, some like to rely on content.
  • Delivery time: What time of the week and day are your users free to interact.

How to A/B test your emails?

Now that you know what you’ll be testing, it’s time to dive into how you’ll run A/B tests on your email campaigns.

Step 1. Choose what you want to test

While it’s good to test multiple aspects of your email campaigns, it’s also important to understand you can’t test everything at once. If you want to test everything to design the perfect (or at least the next best thing) email campaign, you’ll have to run A/B tests multiple times.

  • CTA
  • Delivery time
  • Personalization
  • Who am I writing to?
  • What do I want users to do after reading my email?
  • What metric will I use to measure the results? (example: open rates)

Step 2. Determine how you’ll measure your success

Decide how you’ll measure success for your email campaign before launching your email A/B test.

Step 3. Choose your audience

Oftentimes, companies have multiple target audiences. Depending on your company and users, you should choose if you want to email your entire list of subscribers or a select few. Once you’ve selected your audience, take two small subsets from that sample for A/B testing.

What are some of the best practices you can follow?

Email marketing tools like Unlayer Studio, with drag-and-drop email builders, help speed up your email campaign process. They also contain useful tools to help you with A/B testing your email campaigns. However, the sword no matter how sharp is only as skilled as the one wielding it.

Start with a game plan

For the highest chance of getting positive conversion results from an A/B test, you must have a hypothesis (game plan) to explain why one variation may perform better than the other.

  • We believe using an image instead of just text will engage the readers more efficiently and help them perform our desired action.

Pick your battles

Whether you’re changing subject lines, button colors, or copy, you’ll probably have to run multiple A/B tests.

  • Confidence: How confident are you that the change will be beneficial?
  • Ease: How easy is it to come up with the variations?

Keep a record

As a business, you’ll run multiple email campaigns. In fact, before and after any event, chances are you’ll need to send an email campaign. With that in mind, it wouldn’t make much sense to A/B test everything every time.

Final Words

Start A/B testing your email campaigns now for better engagement and higher click-through rates. The process is quite simple, come up with a hypothesis of what you want to test, set up your A/B test, send it to your subscribers, and wait for the results.

  • Prioritize what you want to test
  • Run tests on all critical elements of your email campaign
  • Use the right tools for an increased impact on your emails.



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Muhammad Ahmad

Muhammad Ahmad

I Design Stuff! — UX Designer & Writer