Subject Line A/B Tester
Optimize Your Email Subject Lines
Compare two subject line variants to determine which one will perform better for open rates and engagement.
100% Client-Side
Dark/Light Mode
Privacy Focused
Performance Metrics
Compare Subject Lines
Variant A
0/60 characters
Your Company
newsletter@yourcompany.com
10:30 AM
Don’t miss our biggest sale of the year!
Preview text would appear here. Keep it compelling to drive opens after they read your subject line.
Variant B
0/60 characters
Your Company
newsletter@yourcompany.com
10:30 AM
Your exclusive 50% off ends tonight!
Preview text would appear here. Keep it compelling to drive opens after they read your subject line.
Variant A Wins!
Based on our analysis, Variant A is likely to perform better
Variant A scored higher in several key metrics that influence open rates including clarity, urgency, and personalization. While both subject lines have strengths, Variant A’s combination of elements makes it the better choice for most audiences.
Performance Metrics
Open Rate Potential
A: 78% | B: 65%
Clarity Score
A: 92% | B: 85%
Urgency/Scarcity
A: 45% | B: 88%
Personalization
A: 30% | B: 60%
Emotional Appeal
A: 75% | B: 68%
Tips to Improve Your Subject Lines
- Keep subject lines under 50 characters for mobile optimization
- Use action verbs to create urgency (e.g., “Shop now”, “Don’t miss”)
- Include numbers or statistics when possible (“5 tips to…”)
- Personalize with the recipient’s name or location when appropriate
- Test emojis sparingly – they can increase or decrease opens depending on audience
- Avoid spam trigger words like “free”, “guarantee”, or excessive punctuation