What is Preheader?
A preheader is the preview text that appears after the subject line in email clients, providing additional context to encourage opens. It's the second chance to grab attention.
The preheader (or preview text) is the snippet of text that appears alongside or below the subject line in email client inbox views. It's your second headline—working with the subject line to convince recipients to open.
Preheader behavior varies by email client: - Gmail shows ~100 characters on desktop, less on mobile - iOS Mail shows more text in portrait than landscape - Outlook shows varying amounts based on layout settings - If no preheader is specified, clients pull from the email body
To set a preheader, include it at the start of your HTML email body (often in hidden text), or use dedicated preheader markup. Many email services provide a preheader field separate from the email body.
Common preheader mistakes: letting default text show ("View in browser"), repeating the subject line, or writing text that gets cut off awkwardly.
Why Preheader Matters
Preheaders can significantly impact open rates—they're prime real estate in the inbox. A compelling preheader creates curiosity, adds context the subject line couldn't fit, or provides a second reason to open. For transactional email, preheaders can confirm the email is expected (e.g., 'Your Acme Corp password reset link is inside').
Frequently Asked Questions
What's a good preheader length?
Aim for 40-100 characters. Front-load the important content since it may be truncated. Write multiple versions: short for mobile, longer for desktop, with natural cutoff points.
Should every email have a preheader?
Yes. Without a specified preheader, clients will show the first text from your email body—often 'View in browser' or navigation links. Always specify preheader text to control what recipients see.
How do I hide preheader text from the email body?
Use CSS to hide the preheader div (display:none) after it's picked up by email clients. Some services handle this automatically. Ensure it still renders in clients that ignore CSS.
Can I A/B test preheaders?
Yes, and you should. Preheaders significantly impact opens. Test different approaches: urgency vs. curiosity, benefit-focused vs. content preview, emoji vs. no emoji.
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