Email subject line tester

Paste a subject line and see what the inbox sees — its length, where it gets cut off on mobile, spam-trigger words, and a live preview of the row your reader actually scans.

Inbox preview

Gmail truncates the subject around 70 chars on desktop and ~33 on a phone; the preheader fills the rest of the line. Everything runs in your browser — nothing is uploaded.

Write a subject worth opening, then send it with emit

emit turns your RSS feed into a newsletter and sends from your own domain — billed per email ($1.60 / 1,000), no subscriber tiers. Good subject, clean deliverability, no monthly fee.