Preheader Generator
Give us a subject. We'll write five preheaders that amplify it — none of them just restate it.
How this works
The preheader is the gray secondary line in your inbox preview. In Gmail and Outlook web, you get ~90 characters; in iOS Mail and Outlook mobile, closer to 40. It is the single most underused inventory in email marketing.
The mistake everyone makes: restating the subject. That's a wasted second impression — you're getting double airtime in the preview and burning it on redundancy. The preheader's job is to amplify the subject, not echo it.
We generate five preheaders that each take a different compounding angle: a specific number, a social proof signal, a soft second hook, a what-not-to-do, and a credibility cue. Each gets a synergy score (1–100) showing how well it pairs with your subject.
For best results, paste the email body too. Without it, we have to infer the email's content from the subject alone, which limits how specific we can be.
Want this on every email you send?
Sign up free and get unlimited runs of every tool, plus a one-screen editor that rewrites, scores, and generates subject lines, preheaders, and CTAs in seconds.