How often should I be A/B testing my emails?

What is A/B testing?

In Email Marketing, A/B testing is testing two variations of the same email to see which one performs the best. Marketers will randomly split their audience, showing half version A and the other half version B. They will then analyse which version performed better in achieving the set goal, such as click rates, sales, or conversions. This allows us to optimise campaigns, flows and pop-ups to their full potential in data-driven decisions such as subject lines, headers, or call-to-actions.

A/B testing allows you to make these choices that can help boost conversions, increase engagement, and, most importantly, A/B testing helps you better understand your audience.

Key steps in an A/B test: choosing one item to test at a time

When A/B testing, it is very important that you only test one thing at a time. For example, if you wish to test which subject line works best for an email campaign or an email in a flow, make sure that’s the only thing you test. This is because if you test multiple things at a time and analyse both variations after, the results will be for multiple changes, not just one. Meaning you wouldn’t know which test subject of the A/B test actually caused the desired goal.

Secondly, you should always make sure your sample set for the test is large enough, e.g. a subject line, headers, imagery. This ensures that statistically there is significance in testing, making sure that you can detect real differences between variations.

A/B testing in flows, campaigns and pop-ups

In flows, A/B testing helps refine triggered messages to deliver the right content at the right moment. In campaigns, it reveals which creative/strategic elements resonate most with your audience before you scale a send. And with pop-ups, testing layout, timing, and incentives ensures you’re capturing as many high-intent subscribers as possible. Together, these tests create a feedback loop that can reach any desired goal.

Beyond optimising individual touchpoints, A/B testing also uncovers broader behavioral insights that inform your entire marketing strategy. Over time, these learnings can help you improve your approach, ensuring every decision you make is backed by real user behaviour rather than a guess.

How often should I be A/B testing?

A/B testing should be considered a core and ongoing task, not just a one-time thing. This allows you to keep up with constantly evolving customer preferences, market trends, and technology. However, it ultimately depends on your sending volume and how quickly you can gather meaningful data. Most companies tend to conduct an A/B test at least 2-5 times a month. During these test times, you should aim to cover full business cycles and document all the data and samples you’ve previously collected for comparison. Each test should typically run for at least 1-2 weeks, which ensures that there is no seasonal interference or any sample pollution.

If you’re unsure whether you’re testing too often or not enough, our team at Get Better is here to help. Reach out anytime, and we’ll guide you toward a testing cadence that fits your goals.