Preheader text
The short inbox preview shown after an email subject line, used to add context before the recipient opens the message.
See it
What it is
Preheader text is the preview snippet many inboxes show beside or below an email subject line. It usually comes from the first readable text in the message, so email templates often place a short hidden line at the top to control it. In Gmail, the snippet helps a recipient judge the message before opening it.
Write it as the subject line's second beat. Add a missing detail, deadline, benefit, or action instead of repeating the subject word for word. Put the intended preheader first in the HTML and check real inbox previews because clients expose different amounts of text.
Gotcha: an empty or badly hidden preheader can make the inbox pull in 'View in browser', navigation labels, or image alt text. Hidden HTML also needs testing across clients. A technique that disappears in one renderer can leave stray text or spacing in another.
Ask AI for it
Write five subject line and preheader pairs for this email, with each preheader adding new information instead of repeating the subject. Keep every preheader under 90 characters, front-load the important words, and return production-ready HTML using a first-child span with the CSS properties display:none, max-height:0, overflow:hidden, and mso-hide:all. Include the visible fallback if a client ignores those properties, and provide a Litmus test matrix for Gmail, Apple Mail, and Outlook.