Critical Impact How To Increase Opens

How to Increase Opens With Eye-Catching Subject Lines and Preview Text

January 19, 2023

With a few simple adjustments, you can generate more opens and increase subscriber engagement.

If you want to increase open rates, you should focus on everything the subscriber sees before they choose to open the message or ignore it. This includes the from address, subject line, and preview text. Since you’re probably using a from address that’s easily recognizable for your brand, we’re going to focus on creating great subject lines and preview text.

Write an Attention Grabbing Subject Line

Create subject lines that stand out in the inbox and prepare subscribers for the content they’ll see in the message. Generate interest by clearly communicating what they’ll find when opening the message.

1) Optimal Subject Length

The length of your subject line should be fairly short. Typically 0-10 words yields the highest open rate (Invesp, 2021). However, it really depends on your specific group of subscribers, which is why the next tip is all about testing.

2) Test Subject Line Performance

It’s always best practice to run an A/B test to see what subject lines perform best with your specific group of subscribers. For example, you could run a subject line test between one subject with 5 words and one subject with 15 words. Then you’ll know exactly what works best for your list.

It’s always helpful to have the right tool for the job, to save you time and effort and you test various subject lines. Critical Impact’s A/B test tool can select random test segments from your subscribers to receive subject line A and subject line B for an unbiased test. The A/B test tool can also automatically send the subject line with the highest opens to the majority of your list.

3) Avoid Spam-like Words and Punctuation

Avoid using Spam-like words in the subject line, to help your message land in the inbox. For example, don’t use words like: free, guarantee, credit card, sex, etc.

Resist the temptation to use all capital letters or excessive punctuation as well, since they can make your email look like spam. So, instead of using the text “EXCITING NEWS!!!!” in a subject line, it would be better to reformat the text as “Exciting News.”

4) Don’t Mislead Subscribers

It might be tempting to use a subject line you’ve heard performs well, like “Re: Follow-Up,” that a subscriber would receive from a co-worker. However, when the subject line is misleading or does not match the content of the message, it can have disastrous results. Your subscribers may get frustrated and mark your message as junk, which will hurt your sender reputation.

It’s better to be clear about the subject and nature of your message in the subject line, instead of trying a gimmicky technique.

Customize Preview Text to Generate Interest

Many focus on developing a good subject line and from address, but completely forget about the preview text. Don’t miss out on this opportunity to increase opens!

1) So, What is Preview Text?

Preview text is the short text that follows the subject line when an email is viewed in some email clients, highlighted in yellow below:

Preview text

Preview text is automatically extracted from the message body, and is typically the first line of text in the message. Sometimes it’s easy to add a specific line of text to the beginning of a message, however, sometimes it’s not possible to add extra text to the very top of an email. To solve this problem, you can easily customize the preview text without having to add a line of visible text to the top of your emails. Critical Impact’s preview text option is added to the top of the message, but is hidden when the email is opened.

2) Select the Most Important Information

Inboxes can display anywhere from 35 – 140 characters of the preview text, depending on the email client and browser width. So you should order the most important information at the beginning of the sentence.

When writing the preview text, focus on the most important piece of information. By selecting the most signification sentence, your subscribers will be able to see the key offer so they know what is contained within the message. This also clearly sets their expectation for what the message contains.

3) Remember the Subject Line

The subject line and preview text are displayed right next to each other. Make sure the preview text works well with the subject line. To make them play off together, think about how the subject and preview text will be displayed, and how the preview text can add more meaning to the subject. This should go without saying, but don’t use the same exact text in the subject line as in the preview text.

In Summary

There are many ways to increase your open rates. It’s our hope that these 7 tips serve as inspiration as you keep on refining and improving your email marketing for greater impact and greater results.

At Critical Impact, our goal has always been to make email marketing extremely simple, and extremely effective. We welcome the opportunity to show you our feature-rich software that marketers find so easy to use for optimizing email marketing performance. To learn more and book a demo, visit