Email Preview Text (Preheader): The Underused Second Headline
Preview text — the snippet next to your subject line in the inbox — is significantly underused. Most marketers leave it blank, which lets email clients pull a random first line of body text instead. Here's how to use it deliberately.
What Happens If You Leave Preview Text Blank
Many marketers leave the preview text (preheader) field blank, which causes email clients to pull the first line of body text — often something like "Having trouble viewing this email? Click here." That's a wasted opportunity: the preview text sits right next to your subject line in the inbox and functions as a second headline.
Recommended Preview Text Length
| Client | Preview text shown |
|---|---|
| iPhone Mail | ~90 characters |
| Gmail (mobile) | ~85-100 characters |
| Gmail (desktop) | ~100+ characters |
| Outlook | ~40-70 characters |
For the complete interactive reference with all fields for every platform, visit our all-platforms character limit cheat sheet — with 16 platforms in one page and links to dedicated tools for each.
How to Set Preview Text Deliberately
Setting preview text of 40 to 90 characters gives you a second line of subject copy, effectively doubling the information you can communicate before the recipient opens. Most email service providers (Mailchimp, Klaviyo, HubSpot) offer a dedicated preheader field separate from your email body — use it rather than relying on the first line of content.
Preview Text Strategy by Subject Line Length
- Short subject line (under 30 chars): use the preview text to add missing context or a secondary hook
- Long subject line (45+ chars): use the preview text to reinforce the first few words rather than introducing new information
- Never duplicate the subject line verbatim in the preview text — it wastes the extra space
Common Preview Text Mistakes
- Leaving it blank and letting "view in browser" links or legal disclaimers fill the space
- Writing preview text longer than the shortest common client display (~40-70 chars), so key words get cut
- Repeating the exact subject line instead of extending it
See our full email subject line length guide and cold email subject line data. For similarly structured "two-part" SEO snippets, see our meta description SEO guide and SERP CTR tips.
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