Preheader Text

Preheader text is the short line of text that appears in an email inbox preview alongside or below the subject line, visible before the recipient opens the email, which can extend the subject line’s pitch and increase open rates.

What Preheader Text Means in Marketing

When someone looks at their inbox, they see three pieces of information for each email: who sent it, the subject line and, on most modern email clients, a short preview of the email content. That preview is the preheader.

Most marketers obsess over the subject line and ignore the preheader entirely. Their emails arrive with preheaders that read “View this email in your browser” or the first line of boilerplate footer text. This is the equivalent of writing a compelling headline and then putting irrelevant small print directly beneath it.

The preheader extends the subject line’s job: to earn the open. A subject line that creates curiosity can be supported by a preheader that adds specificity. A subject line that makes a claim can be supported by a preheader that adds evidence. Used well, the two elements work together as a pitch unit.

How Preheader Text Works

How it renders. Most email clients, including Gmail, Apple Mail, Outlook and Samsung Mail, display the preheader alongside or beneath the subject line in the inbox view. The exact display varies: some clients show it on the same line, some on a new line. The length shown varies by client and device. Mobile clients typically show less than desktop.

The technical implementation. If no preheader is set, the email client grabs the first readable text from the HTML body. Setting a preheader explicitly prevents the fallback. Email service providers typically include a dedicated preheader field in the campaign setup. At the HTML level, a preheader is a span element near the top of the body with styling that hides it visually while keeping it readable by the email client.

Writing effective preheader text. The preheader should complement the subject line, not repeat it. If the subject line says “Your October report is ready”, the preheader should add new information: what the report covers or what the reader will find useful in it. If the subject line creates curiosity, the preheader can increase tension rather than resolve it prematurely. One thing it should never do is simply echo the subject line in different words.

Testing. Preheader text can be A/B tested in the same way as subject lines. Testing a preheader that adds specificity against one that adds social proof, or against one that creates urgency, can reveal what your specific audience responds to.

Preheader Text Example

A brand sends a promotional email with the subject line “Something new for your home office.” The default preheader would pull the opening text of the email, which starts with a navigation menu. Instead, they set the preheader to “The standing desk everyone at the studio switched to.” The subject creates curiosity; the preheader delivers a specific, credible detail that gives the reader a reason to open. Open rate on that campaign comes in above their average.

Why Preheader Text Matters for Marketers

The preheader is the second most visible element in the inbox. Leaving it to chance means your emails consistently waste their second line of pitch. Setting it intentionally is five minutes of additional effort per campaign that reliably improves open rates when done well.