How to Increase Email Open Rates with Email Subject Line Testing

Email open rates are integral in determining the success of your email marketing campaigns. Subject lines can have a decisive impact on your email open rates. In this article, we will explore how to increase email open rates with email subject line testing. 

Email marketing is one of the most effective marketing strategies for businesses to reach their target audience. Every business relies on email marketing to send its message across. It is important to stand out from the crowd and get your emails opened. The most critical factor in email marketing success is the email subject line.

Subject lines can decide the fate of your emails. It can end up in your email being opened or moved to the trash. Let’s explore how to boost open rates with email subject line testing.

Boost Your Email Open Rate

Try for Free!

What is Email Subject Line Testing?

Email subject line testing is the process of experimenting with different subject lines. It is done to determine which ones resonate best with your subscribers. It involves creating variations of your subject lines and sending them to a small subset of your email list. Subject line testing determines which lines perform best and then uses that knowledge to improve your open rates.

Why is Email Subject Line Testing Important?

Your subscribers see email subject lines when they receive your email. A great subject line can grab their attention and encourage them to open your email. On the other hand, a poor subject line can lead to your email being ignored or even marked as spam. Email subject line testing is crucial because it helps you understand what resonates best with your subscribers. It will help you improve your email marketing campaigns over time. Here are some of the prominent keywords that are used in subject lines.

Subject line - Email
Tips for Email Subject Line Testing

Here are some tips to help you get started with email subject line testing to boost your email open rates. 

  1. Use A/B Testing
    A/B testing is a method where you send two versions of your email to a small subset of your email list. Each of them contains different subject lines. The results are analyzed to determine which subject line performs better. The winning subject line can then be used for the rest of your email list. A/B testing is an excellent way to find out what works and what doesn't work for your audience.
  1. Keep it Short and Crisp
    A great subject line should be concise and to the point. Most email clients snip subject lines that are too long. Hence, it's important to keep them brief. A good rule of thumb is to keep your subject lines around 50 characters or less. This ensures that your subscribers can read the entire subject line, even on their mobile devices.
  1. Personalize Your Subject Lines
    Personalization is a great way to make your subscribers feel valued and increase your open rates. Use your subscriber's name or other personal information to make your subject line more engaging. For example, "Mark, don't miss out on our latest offer" is more personal and engaging than a generic subject line like "Our Latest Offer."
  1. Use Urgency or Curiosity
    Creating a sense of urgency or curiosity in your subject line can increase open rates. Make use of phrases like " Here’s the Last Chance" or "Do not Miss Out" to create a sense of urgency. Use phrases like "Find Out" or "Discover Secrets" to pique your subscribers' curiosity.
  1. Test Different Types of Subject Lines
    Different types of subject lines can resonate with different audiences. Experiment with different types of subject lines, such as questions, lists, jokes, or puns, to see which ones perform best. You gain valuable insights into what works best for your audience by testing different subject lines.
    Creating captivating subject lines can have a positive impact on your email open rates. Use action-oriented language, personalization, and urgency to create a sense of curiosity. Write subject lines that encourage recipients to click through to your email.
  1. Timing
    Another strategy is to optimize your email send times. The timing of your email delivery can increase your email open rates. Analyze your email campaign metrics to discover the optimal times for sending emails to your audience. Consider time zones and the recipient's work schedule when determining the best time to send.
  1. Analyze Your Data
    Use analytics tools to track your open rates and analyze the success of your subject line testing. Use the data to adjust your strategy and improve your open rates over time. By analyzing your data, you can gain insights into what works best for your audience and continually improve your email marketing campaigns.
  1. Segmentation
    Segmentation is another powerful strategy that can help increase email open rates. By segmenting your email list based on various criteria such as demographics, purchase history, and engagement level, you can create highly targeted campaigns that are more likely to be opened and acted upon.


Increasing email open rates requires a multi-pronged approach that involves crafting compelling subject lines, optimizing send times, personalization, segmentation, and list cleaning. By implementing these strategies and regularly testing and analyzing your email campaign metrics, you can boost your open rates and achieve greater success with your email marketing efforts.

Get Started with GetShow

Try for Free!