What is an email preheader?

Email preheader

An email preheader is the short line of text that appears after the subject line in your inbox. Think of it as a preview sentence that gives subscribers a reason to open your email before they commit to clicking.

Most email clients pull this text automatically from the first line of your email body, but you can (and should) set it intentionally. When you do, you control what subscribers see alongside your subject line, turning that preview space into a second chance to earn the open.

Why preheaders matter for open rates

Your subject line does the heavy lifting, but it doesn't work alone. Subscribers scan their inbox quickly, and the preheader either reinforces your subject line's promise or undermines it.

A well-crafted preheader adds context. It answers the question your subject line raises, teases what's inside, or creates urgency that tips someone from "maybe later" to "let me see this now."

A neglected preheader does the opposite. When you skip setting one, email clients pull whatever text comes first in your email, which might be "View in browser" or "Having trouble viewing this email?" Neither inspires action.

How to write an effective preheader

The best preheaders work with your subject line, not against it. They extend the message rather than repeat it.

Complement, don't duplicate. If your subject line announces a sale, your preheader can specify the discount or deadline. Same information, different angle.

Lead with the hook. Mobile screens cut preheaders short, so put your most compelling words first to ensure they survive truncation.

Match the tone. A playful subject line followed by a stiff preheader creates friction. Keep the voice consistent so the transition feels seamless.

Include a soft call to action. Phrases like "See what's inside" or "Your code is waiting" give subscribers a nudge without feeling pushy.

Preheader length guidelines

Desktop email clients display more preheader text than mobile apps. On a laptop, you might see 120 characters; on a phone, you might see 40.

Write for mobile first. Front-load your message so the essential words appear even on smaller screens, then extend the preheader to fill the desktop view and prevent your email client from pulling in unintended body text.

A safe range is 40 to 100 characters. Shorter preheaders risk getting padded with body copy, while longer ones get cut off, though at least you control what shows.

Common preheader mistakes

Leaving it blank. Email clients will fill the space with whatever they find first, often navigation links, alt text from images, or unsubscribe language.

Repeating the subject line word for word. You've wasted valuable real estate. Subscribers already read the subject line, so give them something new.

Writing a preheader that doesn't match the email content. If your preheader promises a discount but the email is a product announcement, you've broken trust before the subscriber finishes reading.

Ignoring mobile preview. Always send a test email and check how your preheader renders on a phone. What looks perfect on desktop may cut off mid-sentence on mobile.

How to add a preheader in ActiveCampaign

In ActiveCampaign, you set your preheader in the same place you write your subject line. No code required.

1. Open your email campaign in the editor
2. Click the subject line field at the top
3. Enter your preheader text in the "Preview text" field below the subject line
4. Send yourself a test to confirm it displays correctly

This keeps your preheader separate from your email body, so you can craft it intentionally without worrying about hidden div tags or CSS tricks.

Preheader examples that work

Subject line: Your cart is waiting
Preheader: Complete your order before these items sell out

Subject line: New guide: Email design in 2024
Preheader: 12 templates you can steal today

Subject line: You're invited
Preheader: Join us live on Thursday at 2pm ET

Each preheader adds specificity. The subject line opens a loop, and the preheader gives just enough detail to make opening feel worthwhile.

For more on crafting emails that get opened and read, explore our guide on how to write an email or dive into email design best practices.

FAQs

What's the difference between a preheader and preview text?
They're the same thing. "Preheader" is the technical term, while "preview text" describes what subscribers actually see. Use whichever term your email platform uses.

Do all email clients show preheaders?
Most do, including Gmail, Apple Mail, Outlook, and Yahoo. Display varies by client and device, which is why testing matters.

Can I use emojis in preheaders?
Yes, and they can help your email stand out in a crowded inbox. Use them sparingly, though: one well-placed emoji adds personality, while three in a row looks cluttered.

Should my preheader match my email's first sentence?
Not necessarily. If your first sentence makes a strong hook, letting it pull into the preheader works fine, but setting a custom preheader gives you more control over the message.

Ready to put your preheaders to work? Start a free ActiveCampaign trial and see how easy it is to craft emails that get opened.