Newsletter Editor: What is A/B Testing? How Can I Run an A/B Test in CleverReach?

A/B testing (or “Split test“) allows you to compare two different newsletter versions to identify the more successful one for your email marketing.  

A small part of your recipients receives version A of your email, another part of them receives version B.

This comparison shows you which version your recipients like better. You can analyze and optimize your newsletter campaign and therefore not only increase your open rates, but also boost your sales.

This help center post gives you everything you need to know about A/B testing:

Which Variables Can I Compare in an A/B Test?  

1. Subject and Preheader

The subject line is one of the central and most significant elements of your newsletter. It often decides whether a newsletter gets opened, read or directly deleted.

A/B testing allows you to test, for example:

- length of your subject line
- personalized vs. generic subject line
- funny or serious approach
- phrase different preheaders to arouse you readers’ interest
- ask questions
- use different punctuation marks
- lots of other options (special characters, phrases)


2. Newsletter Content

When recipients open your newsletter they want to like what they see and find what’s promised in the subject line. If you want to test the content of your newsletter, you have several options:

  • Layout
    • Newsletter design, structure, use and design of CTAs (Call-to-action) Buttons
  • Visual elements
    • Images, font types and colors, background colors 
  • Appeal
    • Do you readers prefer a more formal or informal style? 
  • Content
    • Headlines, length, phrases, sequence of topics, call-to-actions, descriptions etc. 
  • Length
    • What is more popular? A long or short newsletter? 
  • Promotions
    • Discount code(s), coupons or free shipping? What do your customers prefer? 

3. Subject Line & Newsletter Content 

You can also use A/B testing to compare different subject lines and newsletter content at the same time.

Please note: If you test more than one parameter, the result of your A/B test won’t be clear. For example, if you test two subject lines and different layouts, you don’t know which variable actually makes one version more successful than the other one. 

The result you get after an A/B test refers to the test in general.

What are the Benefits of A/B Testing?

A/B testing helps you find out what your recipients like and what they are interested in. The test is a subjective comparison showing the preferences of your target group.

Get free and immediate insights into what makes your recipients open and read a newsletter. This increases your open and click rates and in the long run also your conversions.

Running an A/B Test with CleverReach

You can start an A/B test in our email marketing tool by navigating to [Email] – [Create New Email] and selecting [A/B Test].

By clicking the blue button [Test New Editor] you can create your A/B test in the new editor:


Select your recipient list for the split test in the next step. The recipient list must consist of at least 10 recipients.
In case there are less recipients in your recipient list, you automatically receive a notification. 

Good to know: You can also select a segment for your A/B test.

Continue with defining the settings for your email (e. g. sender name, subject A vs. subject B, sender email).


When scrolling down you can define the [A/B Test Settings]:

  • how do you want to divide the campaign? 
  • how do you want to determine the winner version (automatically or manually)? 
  • how long do you want the test to be running (select between a number of hours or days)? 


Click on [Continue] and select a template for your newsletter. After that you can adjust and edit your mailing.


When having defined all settings, click on [Continue], to end up at the final checkpoint before starting your test.


If everything has been set up correctly, you can define a starting point for your newsletter delivery or start the test right away. 

What Happens Once the Newsletter is Delivered or the A/B Test is Completed? 

After your specified test duration has ended, we determine the more successful newsletter version.

If you’re comparing two subject lines based on the open rates, the evaluation shows the version with the higher open rate as the winner.
The winner version will be sent out to the rest of your recipients.

Help & Support

If you have any questions or need further assistance, please contact our service team at any time.