Boost Your Open Rates with Email Preheader

What is a Good Email Preheader?

A preheader is the line of text that appears immediately after the subject line in the inbox. Think of it as a mini-marketing pitch that convinces recipients to open your email. It’s a secondary subject line that complements your primary subject line. What you should never do is repeat the subject line in the preheader.

Although preheader text and preview text both provide more context about the email content, there’s a clear difference. Preview text is automatically generated, but with a preheader, you have control. If you leave the preheader blank, some email clients will display a snippet of preview text instead, or worse, nothing at all. And that’s something you want to avoid.

You see that it’s essential to take control and write a strong preheader. In Flexmail, you can easily add a preheader, so your message is presented optimally in the inbox.

In the Flexmail app, you can write a preheader of up to 100 characters, but we recommend keeping it between 30 and 80 characters. On mobile devices, you’ll only see 30 to 55 characters, depending on the email client and screen size.

To ensure your message always comes across well, place the most important information in the first 33 characters. This way, the core message remains visible, even if the preheader is truncated.


Would you like to know more about what a preheader is, how it differs from preview text, and why the preheader is so important? Then be sure to read this blog.

Why is the Preheader so Important?

The subject line and preheader are the only messages that everyone will see. In a crowded inbox, they determine whether your email is opened or ignored. A strong preheader is therefore indispensable in your email strategy.

A good preheader...

• reinforces the message of the subject line.
• increases open rates.
• leads to more engagement, clicks, and conversions.
• has better deliverability, and thus less chance of ending up in the spam folder

Want to create better subject lines immediately? Check out our subject line cheat sheet.

How to Write a Good Preheader Text?

As you now know, a good preheader is short, powerful, and relevant. It's an addition to the subject line that adds extra value for the recipient and grabs their attention. Try to write a captivating sentence that makes the recipient curious and connects to the email content.

But how do you approach this best? The possibilities are endless: play with words, use humor, ask a question, or give a sneak peek of what's in the email. We'll summarize the most important best practices for you.

1. Add a Call-to-Action

CTAs don't just belong in the subject line or in the email copy. By adding them to your email preheader, you encourage recipients to take action immediately.

You can write a direct CTA by using action-oriented language. For example, “Claim your discount,” “Open this email and discover…,” or “Shop now and get 10% off.” This encourages your recipients to open your email and read on.

Keep these 3 simple rules in mind for a good preheader with CTA:

• Make sure the call to action is short and precise.
• Make it easy to execute.
• Explain the benefits of taking the action immediately.

Need more tips? Read our 11 tips for effective email call-to-actions.

2. Play on Exclusivity

Create the feeling that your recipient is privileged and unique. Using words like "Only for you," "Exclusive for subscribers," or "VIP access" gives your readers the feeling that they're getting access to something special and limited. This can convince them to open the email and participate in a special offer or action - specifically for them!

3. Use FOMO to Create a Sense of Urgency or Scarcity

FOMO (Fear Of Missing Out) is a powerful technique to encourage recipients to take action quickly. By emphasizing urgency, such as time-limited offers: "Only 2 hours left for this deal" or exclusive access: "Only 24 hours available," you create the impression that they're about to miss something important. This motivates recipients to open your email and take action immediately.

Additionally, you can use scarcity by pointing out limited availability, such as "Only 10 items in stock" or "Top deals: When they're gone, they're gone." Numbers and deadlines strengthen the effect and make the message concrete. Combine this with a clear call-to-action and personalization to increase the impact and boost your email's open rate.

4. Stand Out with Humor

Want to stand out in a crowded inbox? A playful or unexpected tone not only grabs attention but also piques the recipient's curiosity and increases the chances of them opening the email to find out what's behind it.

Think of funny comments, intriguing questions, wordplay, or surprising twists, such as: "Our summer sale is hot! Literally. We don't have air conditioning." or "Warning: This email contains cute puppy pictures." By using humor, you not only spark interest but also create a positive impression that makes your brand more likable.

Make sure the humor fits your audience and remains relevant to your message:

• Use subtle and lighthearted jokes that fit your brand's tone
• Avoid clichés or controversial topics
• Experiment with styles like self-deprecation or absurd twists to see what works best

When applied correctly, humor can increase your open rate and make your emails unforgettable.

5. Give a Sneak Peek

A well-chosen sneak peek in the preheader is the way to spark curiosity. By giving a short teaser of what the recipient can expect in the email, such as a new collection, an exclusive offer, an important tip, or exciting news, you encourage them to read on.

Examples like "The secret to better sleep (revealed)" or "Discover who the special guest is at our event" show how you can build anticipation. Make sure the preheader perfectly matches the subject line and keeps the promise in the email. This builds trust and not only improves open rates but also engagement with your campaigns.

6. Let Emojis Speak

Using emojis in your preheader can convey emotions, highlight important words, or simply stand out in a crowded inbox and spark interest in the recipient. Think of examples like: “🎉 Big sale! Discover discounts up to 50%” or “☀️ Summer is here - shop your favorites now”.

Keep it subtle and relevant – too many emojis can cloud the message. Test different combinations to discover what works for your audience.

7. Personalize Your Preheader

A personal touch in your preheader can work wonders to grab the recipient's attention and create a connection. By using the recipient's name, referring to previous purchases, interests, or behavior, or adding location-specific information, you make the email feel more relevant.

8. Ask a Question

A question sparks curiosity and encourages the recipient to open the email to find the answer. Ask questions that are relevant to your message, such as "Are you ready for a new look?" or "How do you get more out of your day?" This invites interaction and gets your reader thinking. Keep your question short, powerful, and fitting for the email content, as a clever question can make a world of difference for your open rates!

9. Let the Benefits Speak for Themselves

Instead of focusing on features, emphasize the benefits or unique value proposition that your email offers. By directly communicating the value, you spark interest and motivate recipients to click through.

A powerful preheader shows how your offer makes the recipient's life easier, better, or more advantageous. Use concrete benefits: "Save up to 30% and get free shipping" or "Double your productivity in 5 simple steps." This sparks interest and shows what the recipient can gain.

10. Use Numbers and Statistics

Numbers and statistics in your preheader grab attention immediately and strengthen your credibility. They make abstract claims concrete and provide measurable information that builds trust. For example, "3 easy steps to 50% more revenue" or "87% of our customers recommend us." By combining a specific benefit with an impressive number, you make your message relevant and convincing.

11. Create a List

A list in your preheader provides an overview and makes your email appealing. Lists, such as "5 tips for better productivity" or "10 foods to boost your energy," offer structure and spark curiosity. By using numbers and symbols, they quickly grab attention in a crowded inbox and make the content scannable.

Opt for shorter lists of 3-5 items, start with the most interesting points, and make the last item mysterious to increase curiosity. Test different list lengths and styles, such as numeric or bullet points, to discover what works best for your audience.

12. Implement Social Proof

Show that others value your product or service. This principle plays on the human tendency to follow the behavior of others. By referring to the number of satisfied customers or recommending products by experts, you create a sense of trust and legitimacy. Short testimonials or specific names add extra impact. This technique builds credibility and increases the likelihood of your recipient taking action.

Bonus Tip: Seasonal and Timely Themes in Your Preheader

Adapting your preheader to seasonal events, holidays, or current trends makes your email more relevant and directly addresses your reader. By referring to spring, autumn, or specific holidays (Valentine's Day or a sports event), you show that your brand is current and responds to the needs of the moment. This not only increases engagement but also creates a sense of urgency for time-limited offers or products.

Make sure the timing is right and the tone fits the season or event. Be creative, but keep your brand identity in mind and adjust the message to the email content.

How to Add a Preheader to Your Email?

You can often add a preheader at the top of your email or hide it in the HTML code. But with Flexmail, it's much easier:

1. When creating or editing an email campaign, you'll see an extra field below the subject line field labeled "Preheader".
2. In this field, you can type a short text of up to 100 characters. Remember to keep it short and powerful.
3. Flexmail automatically ensures that your preheader appears after your subject line in the recipient's inbox.

Need Help? Flexmail's AI Generator Has Your Back!

Do you still need help coming up with a good subject line and preheader text after reading our tips? No worries! In the Flexmail app, you can call upon our AI copywriter.

With one click, you'll receive several proposals for the subject line and preheader. All tailored to your campaign and audience. You can tweak them until you find the perfect combination. This increases the chances that your emails not only stand out but are also actually opened!

Ready to boost your open rates with strong preheaders? Start a free demo account and discover how our AI copywriter helps you write perfect subject lines and preheaders.