A preheader is the short preview text that appears next to the subject line in a recipient's inbox before they open the email. Engage Studio provides a dedicated Pre-header field so you no longer need to hand-edit HTML to control this text — without it, inbox providers often show unrelated content, such as unsubscribe text, in the preview instead. Set a Pre-header when you create an Email Template or Campaign, in either the Visual or HTML editor.
The Pre-header field appears directly below the Template subject (or Campaign subject) field in both the Visual and HTML editors, alongside a persistent banner: "Pro-tip: Emails with pre-headers see a higher open rate."
- Email Template: Set a default Pre-header that new campaigns using the template inherit. Leaving the field empty is valid — no Pre-header is sent.
- Campaign: Inherits the Template's Pre-header by default. Entering any value in the Campaign field overrides the Template default for that campaign only, even if the value matches the Template's default.
A live counter (for example, 18/220 characters) tracks length as you type, including any Liquid syntax:
- Above 90 characters, the field notes that "Pre-headers longer than 90 characters will be truncated by most mail providers."
- Above 220 characters, saving is blocked.
The Pre-header field supports Liquid personalization using the same syntax as the Subject field, for example {{ profile.first_name }}.
At send time, Engage Studio renders the Pre-header and inserts it into the email as hidden text, so it appears in the inbox preview next to the subject line without showing in the email body. UTF-8 characters, including Japanese text and emoji, are fully supported.
- Save blocked at 220+ characters: Shorten the Pre-header text to 220 characters or fewer.
- Liquid syntax error on save: Check that merge tags open with
{{and close with}}, matching the syntax used in the Subject field.