What is an email preheader?

An email preheader is a snippet following the subject line providing a preview of the email from the inbox. It’s a simple way to extend your headline copy and increase email open rates, making it an important part of email design.

Note there’s no separate field called “preheader email.” The first 40-70 characters of the message text becomes the email preheader (for mobile email design and desktop design, respectively). If you’re below that limit and you start another sentence under it, both will show in one line. Preheaders can appear below or to the right of the subject line, depending on the device. Email subject lines and preheaders work together to entice the email recipient to open and read the email, so it’s important to craft a message that resonates with your target audience.

How do you write a preheader in an email?

Email preheader best practices:

• The ideal preheader has less than 40 characters, but you can use up to 70 without getting cut off on desktop inboxes.
• Customize the preheader for higher open rates (e.g., Are you joining us, {name}?)
• Keep the format simple or it may not display properly
• Save the email as a draft to preview your preheader