Free email tool

Write a subject line worth opening.

Get a clear score, see what's helping or hurting, and make the next version stronger in under a minute.

0 characters
Paste one subject line. We'll check the words, structure, length, and inbox fit.
Try an example:
Your score will appear here
You'll also get a five-part breakdown.

What to improve

Start with the changes that make the biggest difference.

Want 10 stronger versions?

We'll rewrite your subject line from ten useful angles, so you can pick the one that fits your email.

  • Direct, curiosity, benefit, and question angles
  • Made from the subject line you just tested
  • Free. Unsubscribe any time.

Your 10 improved versions

Use these as starting points. Keep the promise honest and aligned with the email.

What the score checks

Inbox fit

Useful length, careful emoji use, and fewer risky promotional signals.

Reader pull

A clear reason to care, with enough specificity or curiosity to earn attention.

Human touch

Natural phrasing, direct language, and relevant personalization cues.

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