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Email Subject Line Tester

Score your subject line and get stronger versions.

Attach a PDF or doc (optional) for context. AI-generated, so give it a quick read. Free, no signup.

A free email subject line tester for sales and marketing teams. Paste a subject line (and the audience or context if you have it), and it gives a quick score, a short breakdown of what works and what to fix, and five to seven stronger versions built to get opened on mobile. Free with no signup.

How to use it

  1. Paste your subject line, and add the audience or email context if you can.
  2. Press Generate and your score, feedback, and improved options stream in.
  3. Click Copy and test the strongest version against your current one.
  4. Reply in the chat to refine: more curiosity, more specific, or less salesy.

FAQ

Is this subject line tester free?
Yes, it is free and needs no signup.
How does it score my subject line?
It checks the things that drive opens: length and mobile preview, clarity, specificity, curiosity, and spam risk, then gives a quick score and concrete fixes.
Does it rewrite my subject line?
Yes. Along with the score it gives you five to seven stronger versions, most under 50 characters so they are not cut off on mobile.
Does it work for cold email and newsletters?
Both. Tell it the audience or context and the feedback and rewrites will match cold outreach or marketing email.

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