Using an email preheader to enhance a subject line

Best practices for writing an effective email preheader that supports the subject line and increases opens

On most mobile devices (Android and iOS) and major email clients (Gmail, Outlook, and Yahoo), an additional line of preview text displays in the inbox after the subject line to give the reader a better idea of whether or not to open an email. By including a preheader, you can further entice your contacts to open your email.

• Writing a preheader
• How a preheader displays

Writing a preheader

To write an effective preheader, start with a good subject line. The subject line should be short, catch your readers' attention, and stand on its own for those who can't see the preheader.

For an effective subject line and preheader combo, think about what your main idea is and what the call-to-action is. Your preheader should offer some additional detail to support the subject line. The overall effect is to both inform and create a sense of urgency to take the desired action:

Example:

• Subject line - Don't miss October's speaker
• Preheader - RSVP today - space is limited!

Example:

• Subject line - Save up to 30% on select school supplies
• Preheader - Coupon expires Saturday

Example:

• Subject line - Proposed city dog park plan now open for public comment
• Preheader - We need your feedback!

Your preheader can be up to 250 characters long, but we recommend keeping it to 90 characters. The first 5-8 words of the preheader are the most important, though you should still be strategic with the words that follow. Different email clients and mobile devices have different character limits and ways of displaying the subject line and preheader, with some displaying up to 140 characters. Some not only display the preheader but also show the first sentence or two of your email.

Important: If you leave the email preheader field blank in your header options, email clients that display a preheader will replace it with the first line of text in your email. By including a preheader, you can control what your contacts see. With more than 50% of people reading their email on a mobile device, it's an opportunity you don't want to miss!

How a preheader displays

Typically, the email preheader displays to the right or underneath your subject line. Keep in mind that different email clients have different display settings and features, like preview panels, so even though your contacts are using the same email client, they may see the subject line and preheader differently.

Desktop example

In Gmail on a desktop or laptop, the preheader displays to the right of the subject line when the preview panel is disabled.

Mobile device examples

Gmail on an Android device limits the characters for both the subject line and the preheader.	Outlook on the native Android Email app displays the full subject line and leaves room for the preheader.
Gmail on an iOS device limits the characters for both the subject line and the preheader.	Mail, the iOS native Email app, limits the characters for both the subject line and the preheader.

Did you know? You can set up email accounts using free services like Gmail, Yahoo, and Outlook to send test emails to, or you can use Inbox Preview to see what your email looks like on the top five most-used email clients, including both desktop and mobile views.

Questions?