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Jonas · 13 min read · Tips and resources · August 6, 2021

How to increase your open rate with email preheaders

Jordan had Pippen. Simon had Garfunkel. Batman had Robin. To generate higher open rates for your email marketing—you have your own power duo!

Subject lines have email preheaders. 

The email preheader is the first line of text that appears next to the subject line in your recipient’s inbox. On mobile devices, your email preheader text is often more prominent than the subject line. And, good preheaders are proven to help boost your open rates!

Our data shows that most campaigns are not using email preheaders.

People are spending more time online than ever before, which means inboxes are more cluttered than ever. Your subscribers have to be selective about what they open. So give them a compelling reason to open your emails in the email preview text. 

Let’s take a look at email preheaders, and explore ways to combine them with your subject lines to keep your open rates healthy and your email list happy.


The email preheader, also known as the email preview text, is the line of text that is visible in your inbox and provides a short summary of your email. These snippets of text are pulled from your email or newsletter and appear on most mobile devices including iOS and Samsung Galaxy as well as web email clients such as Gmail and Outlook.

email preheader example on mobile device preview text - MailerLite

This important piece of screen real estate provides an opportunity to share a preview and convince readers that the email content contains relevant and valuable information. 

In fact, this email preview text is sometimes referred to as the "Johnson box" in homage to the old direct response marketing wizard, Frank Johnson, who invented a summary text box to entice prospects to a sales letter. 

OK, enough history for the day. Let’s talk about how these preheaders can help you entice your readers to open more email campaigns.


Your subject line and preheader text are the only content that everyone is guaranteed to see. What you write will determine whether or not you get an open. 

Today’s email inbox is a chaotic mob of brands all trying to stand out. And despite having signed up for your newsletter, your subscribers must filter through dozens or even hundreds of emails every day deciding within seconds whether yours is worth opening.

With such high stakes, you need to do everything in your power to remind people why they should be reading your email. Email preheaders will give you a competitive advantage. In fact, our research shows that over 90% of all campaigns sent from MailerLite do not use a custom preheader.

This means that you have an opportunity to stand out from the crowd and show readers that your email is the one worth opening.


We recommend aiming for around a character limit of around 100-140 (an old-school tweet). If your preheader text is too short, it will pick up the text from the body of your email. For this reason, it’s better to keep it over 100 characters to ensure that doesn’t happen. 

If you read 5 articles about email preheaders, you’ll likely get 5 different opinions for the perfect preview text length. One reason is that the character length depends on the email client (Gmail, Outlook, etc.) and device (desktop, mobile, tablet, etc.).

If you have some data that gives insight into where your recipients view most of their emails, you can adjust your preheader length to accommodate the majority of your subscribers. 

If you don’t know, then it’s safer to assume many of your readers are using mobile devices to preview their emails before opening. Some studies suggest as much as 70% of email opens are happening on a mobile device.

Just think of the first 50 characters of your preview text as the most important, and the remaining characters as the icing on the cake.

Also, keep in mind that the length of your email subject line on many desktop clients can dictate the length of your preheader. So keep subject lines below the recommended 40-50 characters to be safe.

​Quick tip 👉

Send a test email to yourself and view it on your devices to see how your preheader displays.


Effective email preheaders follow a lot of the same best practices as writing email subject lines, especially around relevance, personalization, and the ability to test and optimize.

The first step is to scrutinize your email content to uncover the most interesting or important pieces. How can you sum up your content in less than 200 characters (subject line + email preheader)?

Your subject line and preview text should let the reader know exactly what to expect. But only being descriptive is not going to cut it. Your subject line + preheader combination must also be compelling. 

Here are 7 ways to write compelling preheaders.

1. Highlight your email's value proposition

Every email you send should have a goal. Some emails promote special deals or sell products while others share news or content. What is the value to your reader?

Use your preheader to communicate the most compelling benefit of the email. Give your readers a reason to open by highlighting the 1 thing that drove you to create the email in the first place.

Tell subscribers what’s in it for them and they'll be more likely to click. This MailerCheck example highlights its value proposition in the subject line and uses the preheader text to reinforce 2 compelling benefits.

highlight value proposition with email preheader - MailerLite

2. Add a call to action

If you want someone to open your email, sometimes it’s as simple as asking them with confidence. Add a clear call to action (CTA) to your preheader and let people know that opening the email will be worth their time.

This means going beyond the typical CTA, such as “Read now” or “Learn more”, and constructing text that gives them a reason as well as a directive. 

For example, the email below lets readers know that by joining they will receive double rewards.

adding cta call to action text to email preheader - MailerLite

3. Connect your subject line and preheader

Instead of writing 2 completely separate lines of text for your subject line and email preheader, create a more compelling story by combining the 2. 

Because they appear together, you can come up with interesting ways for the subject line and preheader to work together. You can ask a question and then answer it, or start a sentence in the subject line and finish it in the preheader.

This technique can work really well. We like this example below where the subject line presents a cryptic statement that is quickly explained in the email preheader.

combining subject line and email preheader - MailerLite

4. Use email preheaders to build curiosity

Copywriters love to use psychological triggers to inspire readers to take action. One of the more popular approaches is using FOMO (fear of missing out).

You can incorporate curiosity or raise the sense of urgency by using FOMO, but it’s very important that your email delivers on the promise you make in the text. The payoff must match your claim. If it doesn’t, you run the risk of writing clickbait or “spammy” preheaders.

This example from Peet’s Coffee uses FOMO, but it is not over-the-top. Their offer is relevant to the email they are sending.

FOMO email preheader example from Peets coffee - MailerLite

5. Personalize your email preheader

There is no doubt that email personalization improves engagement. When the reader sees something familiar about themselves such as their name, city, birthday, etc., they are much more likely to open your email.

You can add personalization to your email preheaders in the same way you do for your subject lines or email text. If you haven’t used custom fields to personalize your emails, you can learn all about them here.

While using the recipient’s name is the most common use of personalization, most people have come to expect it. You can take personalization a step further by including more information about the recipient. The email preheader example below uses a combination of both the recipient’s name and a specific event they missed.

personalized preheader example tara reed

6. Use (but don’t overuse) emojis

There is no denying that emojis catch your eye and make reading a little more fun. These colorful graphics can also help your email ‘pop’ within a cluttered inbox.

People love emojis, but what about for business? While it’s important to use the appropriate images in a business email, studies have found that 78% of people agree that using emojis makes you seem more likable. 

emoji email preheader text example the remote company - MailerLite

7. A/B test your email preheaders

MailerLite’s A/B testing functionality is an extremely useful way to learn what types of messaging work best with your readers. 

You can test 2 different email preheaders within a campaign and set it up to automatically choose the preheader that generates a higher open rate. 

In MailerLite, you can test preheaders by choosing to test Email content, and then creating 2 emails with the same content except for the preheaders. 

If you are new to A/B testing, check out this tutorial video to see just how easy it is.

testing email preheader with a/b testing - MailerLite

We compiled some of the best-performing subject line + preheader text examples to help inspire your own ideas. All of these lines generated a 50+% open rate.

Subject line Preheader
Time is running out, {$name|default:"friend"}! grab these deals now ...
(Mostly) Good News!! Skip the Line with our Value Bag!
I'm a stunningly bad businessperson. 😕 The entire series all in one book, and all on me!
Dear {$name|default:"Reader"}, I've never done this before. You could win $100 gift card.
This is the Bliss brother you’ve been waiting for! 🎉 Save a horse. Ride Austin Bliss.
Would you like to join my special team? 😘📕📫 Get free books in advance by joining my special team.
Start your 1 month trial today! Unlimited articles + daily digital replica of the newspaper
Your Big Chance to Be Heard 📢 And believe me, I listen.
Poll results 📊 I'm with the majority :)
The 2020 Challenge Started! Here's All The Details And Important Information
Omg, you rocked it, {$name}! Will our winners please come forward? :D
Flash Sale ⌛📦❤ One more week. :)
Rock out to Bob Marley at Vinyl Happy Hour! 🎶 Listen and discuss \Exodus,\" plus hear a live performance of the album!"
My biggest deal ever... and it's one day only.

You can add or edit your preheader text in our drag & drop editor by creating a new email or navigating to edit mode on a current email.  When you click on the block at the very top of your email, you’ll be able to easily add or edit your preheader text—no HTML or coding skills needed.

setting up email preheader using MailerLite drag and drop editor - MailerLite

You also have the option to include the preheader text in your actual email, or you can choose to have it only appear in the preview area of the inbox. In the second option, readers will see the text in their inbox, but it will not appear anywhere within the body of your email.


A final thought on email preheaders

Email preheaders are currently an under-used asset that can really help you get more opens! If most other people are not using preheaders, you have an opportunity to break through the inbox clutter.

Use your subject lines and preheaders to provide more context about why people need to open your email. Give preheaders a try and let us know if you see a bump in your open rates.

Editor's note: This post was originally published in 2014 but has been updated with new data and best practices.


Have you tried using preheaders in your email marketing campaigns yet?

Jonas Fischer

I'm Jonas, Content Manager at MailerLite. I’m not the 4th Jonas Brother, but I do write content (which is similar to being a teen heartthrob). After writing for a bunch of companies over the years, I discovered my professional passion—helping add some humanity to B2B marketing. Email is the perfect place to start!