Email Subject Line A/B Test Generator
Email MarketingbeginnerClaude 3.5 Sonnet or GPT-4o. Both excel at generating creative variations while maintaining brand voice. Claude is slightly better at explaining the psychology behind each variation; GPT-4o generates more diverse options faster.
When to Use This Prompt
Use this prompt when planning email campaigns and you need multiple subject line variations to test. It's ideal for CMOs and email marketers who want to systematically improve open rates by testing different psychological triggers without manually brainstorming variations.
The Prompt
Generate 5 pairs of contrasting email subject lines for A/B testing. Each pair should test a different variable (urgency, personalization, curiosity, benefit-driven, or social proof).
## Email Campaign Details
- **Campaign Goal**: [e.g., product launch, webinar signup, seasonal sale]
- **Target Audience**: [e.g., existing customers, new leads, enterprise buyers]
- **Industry/Product**: [e.g., SaaS, e-commerce, B2B services]
- **Tone**: [e.g., professional, casual, playful, urgent]
- **Key Message**: [e.g., 30% discount, limited time offer, new feature announcement]
## Requirements
For each pair, provide:
1. **Subject Line A** (control/baseline version)
2. **Subject Line B** (variant to test)
3. **Variable Being Tested** (what's different)
4. **Why This Matters** (brief explanation of expected impact)
Keep all subject lines under 50 characters. Avoid spam trigger words. Make them mobile-friendly and compelling enough to drive opens.
## Output Format
Present as a numbered list with clear labels for each pair.
Get the Full AI Marketing Learning Path
Courses, workshops, frameworks, daily intelligence, and 6 proprietary tools — built for marketing leaders adopting AI.
Trusted by 10,000+ Directors and CMOs.
Tips for Best Results
- 1.Specify your actual open rate baseline and industry benchmarks so the AI can suggest variations likely to outperform your current performance.
- 2.Include recent email performance data (which subject lines worked last month) to ensure new variations test genuinely different variables rather than repeating what already succeeded.
- 3.Request the AI include character counts and preview text considerations, since many opens happen on mobile where only 30-40 characters display.
- 4.Ask for subject lines that align with your brand voice guidelines to ensure variants feel authentic and won't confuse subscribers about sender identity.
Example Output
## Subject Line A/B Test Pairs
**Pair 1: Urgency vs. Standard**
- A: "New Feature Available Now"
- B: "⏰ Only 48 Hours: New Feature Launch"
- Variable: Time sensitivity and emoji
- Why: Urgency typically increases open rates by 15-25% when audience perceives scarcity
**Pair 2: Personalization vs. Generic**
- A: "Your Q4 Marketing Strategy Guide"
- B: "[Name], Here's Your Personalized Q4 Plan"
- Variable: Direct name personalization
- Why: Personalized subject lines see 26% higher open rates on average
**Pair 3: Curiosity Gap vs. Direct Benefit**
- A: "We Discovered What Top Performers Do Differently"
- B: "5 Habits of High-Converting Marketing Teams"
- Variable: Curiosity gap vs. clear benefit statement
- Why: Curiosity drives opens but clarity reduces unsubscribes
**Pair 4: Social Proof vs. Feature-Focused**
- A: "Join 50,000+ Marketers Using Our Platform"
- B: "Advanced Analytics Dashboard Now Available"
- Variable: Social proof vs. product feature
- Why: Social proof builds trust and FOMO among hesitant prospects
**Pair 5: Question vs. Statement**
- A: "Ready to Cut Email Production Time in Half?"
- B: "Cut Your Email Production Time in Half"
- Variable: Question format vs. declarative statement
- Why: Questions engage curiosity but statements feel more authoritative
Related Prompts
Related Reading
Get the Full AI Marketing Learning Path
Courses, workshops, frameworks, daily intelligence, and 6 proprietary tools — built for marketing leaders adopting AI.
Trusted by 10,000+ Directors and CMOs.