Subject Line Formulas That Work
Your subject line determines whether your email gets opened. Master these proven formulas to improve open rates across all your campaigns.
The Curiosity Gap
Create intrigue by hinting at valuable information without revealing everything. "The one thing that changed how we think about X" or "What we learned from analyzing 10,000 emails."
Number-Based
Numbers create specific expectations. "7 ways to improve your email open rates" or "3 mistakes killing your conversions." Odd numbers often perform better than even numbers.
How-To Format
Promise practical value. "How to write emails that get opened" or "How we increased conversions by 47%." This format signals actionable content.
Question Format
Questions engage the brain and prompt curiosity. "Are you making these email mistakes?" or "What if you could double your open rates?"
Urgency and Scarcity
Create legitimate time pressure. "Last day: 30% off everything" or "Only 5 spots left." Use genuine urgency only; false scarcity damages trust.
Personalization
Include the recipient's name, company, or relevant data. "[Name], your custom report is ready" or "Special offer for [Company]."
Direct and Simple
Sometimes straightforward works best. "Your order has shipped" or "Monthly newsletter: January 2026." Clear beats clever when relevance is obvious.
Subject Line Best Practices
- Keep under 50 characters for mobile
- Front-load important words
- Avoid spam triggers (ALL CAPS, excessive punctuation)
- Test variations with A/B testing
- Match subject to content to build trust
AI-Generated Subject Lines
Sequenzy generates compelling subject lines alongside your templates. The AI applies these formulas automatically, creating variations you can test.