Tips and Trick for Email A/B Testing

We all are looking for the best results from our Email marketing campaigns – that’s why we must figure out what works best for our audience. A/B testing is the process of sending different Email variations to a subset of your audience – with the goal to find out which Email delivers the better results.

There are different ways that you can A/B test, as simple as sending different subject lines to test which one generates more opens, while more advanced A/B testing could include totally different Email templates – to see which generates more clicks.

The key point in A/B testing is to make small tweaks to maximize your results. Remember that the smallest changes can make big differences!

We’ve put together a few tips and trick on how to run your A/B Testing:

Subject Lines

The Subject Line of every Email is the most important part. It is what your Subscriber sees first and what stands out straight away – it is extremely important to have your Subject Line on point. On most devices, the subject line is formatted with darker, heavier text to help make it stand out among the other details of the email.

But what kind of test can you run on your Subject Line?

  • Word length. Studies show that the perfect length for a Subject Line is around 60 – 70 characters. Every audience reacts differently to different aspects. Set up a A/B test campaign to see which works best for you.
  • Word order. Be aware of how you structure your subject line. Ideally get the key point or metric across first because it can impact how people read and interpret them and can potentially impact your email open rate.
    As examples:
    Use this discount code to get 25% off your next purchase
    Get 25% off your next purchase using this discount code
  • Content. If you are regularly sending out content to the same audience like newsletters, reminders, offers etc then consider using a consistent subject line to build awareness and improve your email open rates. Next time you’re writing a subject line for your email newsletter, consider testing different pieces of content in the subject line to increase the number of opens your campaign receives.
  • Personalization. Including the prospects name as a merge field within the subject line has been shown to increases open rates by almost 14%. For your next email campaign why not try A/B testing it. Example subject line: Sarah, get 25% off your next purchase using this discount code. Additional personalisation can include referencing previous orders, the prospects company name or geographic location.


You should test sending out both Rich Text and HTML emails. There are pros and cons to each and their success will vary dramatically across industries and contact demographics.

Having strong images within your emails can create a more memorable way of getting your message across to your audience and build on your brand identity.

You can A/B test multiple variables, like:

  • Images v No Images
  • Multiple Images v Single Image
  • Different Image Styles
  • Image Personalization
  • Calls-to-Action (Buttons and messaging for contact etc)


To get the best results out of your A/B testing try to understand why one email might perform better than the other.

The ICE score is a way to grade your different A/B test ideas and prioritize which ones to run first.

  • Impact: How big of an impact do you think this might have? Is testing a small change in your subject line likely to have as big of an impact as testing the tone of your copy?
  • Confidence: How confident are you that this change will have a positive impact? Testing proven tactics like personalizing the subject line are more likely to have a positive impact on conversions than changing the image style in your campaigns.
  • Ease: How easy is it to implement this A/B test? Testing the word order of your subject line would take less than 30 seconds, whereas testing different image styles requires you to create multiple images with different styling and will generally take longer.

Remember not every A/B test you run is going to result in an increase in conversions. Some of your variations will decrease conversions, and many won’t have any noticeable effect at all. It is all about testing and remember with every test, you learned more about what works and what doesn’t work for your audience.

Try DemandScience to get the best results out of your email marketing strategy.