You probably already know the value of a/b testing your emails. It helps you make data-driven decisions, which leads to better emails, which leads to better results.
But it’s not just about testing any part of your email. It’s about testing the right parts of your email. When it comes to open rates, there’s no better part of your email to test than your subject line.
So, how do you ensure your subject line a/b tests are successful? Here are 10 best practices for a/b testing your subject lines.
1. Define your goals
Before you start A/B testing your subject lines, you need to have a clear idea of what you’re trying to achieve. In this case, your goals will likely be centered around open rates and engagement.
You could also use A/B testing to see how your audience responds to different types of content. For example, you could test a subject line that focuses on a discount against one that focuses on a new product launch.
Or, you could test different content types, like a blog post round-up versus a single article.
2. Test the right things
It’s easy to get caught up in the idea of A/B testing and forget what you’re actually testing. This can lead to a lot of wasted time and effort.
The most obvious thing to test with your subject lines is the subject line itself. But there are other factors to consider. For example, you could test the length of your subject lines, the use of emojis, or the use of personalization.
3. Make sure your sample size is statistically significant
If you want to be confident that your test results will hold true for your entire audience, you need to make sure your sample size is statistically significant.
This means it needs to be large enough to account for any anomalies or errors that could occur in the test. If you have a small sample size, your results could be misleading and not hold true for your entire audience.
4. Keep it simple
You don’t have to reinvent the wheel every time you test your subject lines. In fact, sometimes the simplest changes can make the biggest differences.
For example, you could test the length of your subject lines. Or, you could test out different emojis. Even just switching up the wording in your preview text can make a big impact.
5. Test one variable at a time
The more variables you test, the more complicated your results will be. Plus, you won’t be able to tell which variable actually impacted performance.
For example, if you test a subject line with one emoji and one without, you won’t know if the emoji or the words themselves made a difference. Instead, test one variable at a time so you can be sure of the impact.
6. Use the right tools
If you want to get the most out of your A/B tests, you need to use the right tools. This means using an email marketing platform that has built-in A/B testing features. These tools make it easy to set up and run A/B tests, and they provide you with all the data you need to analyze your results.
There are a ton of email marketing platforms out there, so take the time to do your research and find the one that’s the best fit for your business. Some popular options include Mailchimp, Constant Contact, and Sendinblue. These tools not only help you test your subject lines but also improve your email visuals—if you’re using blurred graphics or thumbnails, it’s a good idea to unpixelate images before sending, to ensure a clean and professional impression.
If you’re not ready to invest in an email marketing platform, you can use a free tool like SubjectLine.com to test your subject lines. This tool uses AI to analyze your subject line and provide you with a score that indicates how likely it is to get opened.
Another alternative is to test how referral-driven subject lines perform using tools like ReferralCandy. With these tools, you can A/B test your subject lines and track other key email metrics.
7. Consider the time and day
What day of the week and time of day you send your emails can also affect your open rates. This is why it’s important to consider the timing of your A/B tests.
If you have an idea of what day and time you think your email will perform best, you can use the schedule feature in your email marketing tool to schedule your test emails accordingly.
If you’re not sure, you can send your test emails at the same time on different days, or at different times on the same day.
8. Don’t test too often
You don’t want to test your subject lines too often. If you do, you won’t have enough time to collect enough data to make accurate decisions.
In addition, you run the risk of annoying your subscribers if you’re constantly testing your subject lines.
9. Use the results to inform your strategy
A/B testing is a great way to optimize your email marketing strategy. But it’s not the only tool you should use.
For example, if you’re seeing low open rates, you might want to test your timing. If you’re seeing high open rates but low click-through rates, you might want to test your call to action.
You should also use your A/B test results to inform your strategy for future campaigns. For example, if you find that including emojis in your subject line increases open rates, you might want to start doing that on a regular basis.
By using A/B testing to inform your email marketing strategy, you can continue to improve your results over time.
10. Test your preheader text
The preheader is the snippet of text that appears next to or below the subject line in the inbox. It’s the first thing subscribers see when they open their email, and it can have a big impact on open rates.
The preheader text is often the first sentence of the email, but you can customize it to be whatever you want. This is a great opportunity to provide some context for your email, highlight the main offer, or include a secondary call to action.
Conclusion
A/B testing your subject lines can help you learn what your audience prefers and then send more effective emails. Follow these best practices and start experimenting with your subject lines.
