Back to Glossary
Email Structure

Preheader

The preview text that appears after the subject line in email inbox views, providing additional context.

Definition

The preheader is the text that appears in the inbox next to or below the subject line, offering a preview of the email content. Also called preview text, it can be explicitly set in the email code or defaults to the first visible text in the email. Well-crafted preheaders complement the subject line to encourage opens.

Why It Matters

Preheaders are prime real estate for convincing subscribers to open. They extend your subject line's message and provide additional context or intrigue. A good preheader can significantly improve open rates. Ignoring preheaders wastes an opportunity and may show unhelpful text.

How It Works

Preheaders are set using hidden text at the beginning of the HTML email body or through your ESP's preheader field. Email clients pull this text to display in the inbox preview. Length varies by client, typically 40-100 characters are visible.

Best Practices

  • 1Write custom preheaders for every email, never rely on defaults
  • 2Complement your subject line, do not repeat it
  • 3Include your most compelling benefit or hook
  • 4Keep important content in the first 40-50 characters

Frequently Asked Questions

Write 40-100 characters to ensure the most important content is visible. Mobile shows less than desktop. Put your hook in the first 40 characters with additional content after.

Good preheaders add information beyond the subject line, create curiosity, highlight a benefit, or include a call to action. They should work together with the subject line to tell a compelling story.