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Subject Line Tester

Optimize your open rates with our AI-powered subject line tester. Get scores on emotional impact, length, and keyword effectiveness.

AI Subject Line Analyzer

Get AI-powered feedback to boost your email open rates

Powered by Gemini
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Tips for better subject lines:

  • Keep it under 50 characters for mobile
  • Use numbers and statistics when relevant
  • Create urgency without being spammy
  • Ask a question to spark curiosity
  • Personalize with the recipient's name
  • A/B test different versions

About this tool

This free utility is designed to help email marketers and developers improve their deliverability and campaign performance. At Sequenzy, we believe in providing transparent, helpful tools for the community.

Frequently Asked Questions

We analyze your subject line based on proven email marketing best practices. We look at length, sentiment, urgency, power words, and spam triggers.

Generally, subject lines between 30-50 characters perform best on mobile devices, while slightly longer ones can work well for desktop users.

Emojis can increase open rates by making your email stand out, but use them sparingly. One or two relevant emojis work best. Avoid them for formal B2B communications.

Power words are terms that trigger emotional responses and increase engagement. Examples include 'exclusive', 'limited', 'free', 'new', and 'proven'. Our tool checks for these.

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