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Free Email Subject Line Tester
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Paste your subject line and get an instant score with breakdown. Detect spam triggers, urgency gaps, and get 3 ready-to-use alternatives.

Subject Line Analyzer

Type or paste your email subject line

0 / 60

/ 100

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Score Breakdown

3 Suggested Alternatives

Email Subject Line Best Practices

Keep it 30–50 chars. Most email clients cut off at 60. Mobile cuts at ~40.

Use "you" or the recipient's name. Personalized subject lines get 26% higher open rates.

Add a number. "7 ways to..." outperforms generic "Ways to..." consistently.

Ask a question. Questions create curiosity loops that drive opens.

Avoid spam triggers. ALL CAPS, "FREE!!!", "GUARANTEED" land in spam folders.

Create urgency, not panic. "Closes tonight" beats "ACT NOW!!!" every time.

Use power words. Proven, exclusive, secret, new, and instant trigger action.

Test A/B at scale. Even a 5% lift in open rate compounds across your list over time.

Need more? 155 copy-paste AI prompts including email marketing templates.

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Free Email Subject Line TesterScore & Improve Instantly

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Need more? 155 copy-paste AI prompts including email marketing templates.

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Free Email Subject Line Tester
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