Email Preheader Generator

Most email marketers obsess over subject lines and completely ignore the preheader, which is a huge missed opportunity. The preheader (or preview text) appears right after the subject line in every major inbox, and together they form a one-two punch that determines whether someone opens your email or scrolls past it. Getting this combination right can lift open rates by 10-20% without changing anything else about your campaign.

How preheaders actually work in email clients

When you open your inbox, you see the sender name, subject line, and then a snippet of preview text. That snippet is your preheader. If you do not set one explicitly, the email client grabs whatever text it finds first in the email body, which is usually something embarrassing like "View this email in your browser" or a navigation menu. Gmail shows roughly 90-100 characters of preheader on desktop, Apple Mail shows about 80-140, and mobile clients show 40-75 depending on the device and subject line length. The trick is to front-load your best content in the first 40 characters so it works everywhere.

Writing preheaders that complement your subject line

The biggest mistake is repeating the subject line in the preheader. If your subject says "50% off everything today," your preheader should not say "Get 50% off our products." Instead, add new information: mention a deadline, highlight a specific product, or tease what is inside the email. Think of the subject line as the headline and the preheader as the subheadline. For example, subject: "Your cart is waiting" + preheader: "Those shoes are selling fast, only 3 left in your size." Use our subject line tester to make sure both pieces work together before sending.

Common preheader mistakes to avoid

Besides repeating the subject line, watch out for these pitfalls. Do not write preheaders that are too short (under 30 characters), because the email client will fill the remaining space with body text anyway. Do not use ALL CAPS or excessive exclamation marks, as this triggers spam filters. Avoid starting with "Hi [name]," because that wastes prime preview real estate on a greeting. And never leave the preheader blank on promotional emails. If you are running promotions, check your copy with our spam word checker to make sure your preheader is not accidentally triggering filters.

Testing and measuring preheader performance

Preheaders are one of the easiest things to A/B test because they do not require design changes. Run a simple test: send the same email with two different preheaders to a small segment, measure open rates after 2-4 hours, then send the winner to the rest of your list. Use our A/B test calculator to make sure you have enough data for statistically significant results. Track your open rate improvements over time with the open rate calculator to see the cumulative impact of better preheaders on your campaigns.