Email Subject Line Tester

Generates and evaluates email subject lines to maximize open rates. Analyzes character count, power words, emotional triggers, personalization opportunities, spam risk, and mobile preview appearance.

Usage

Describe the email content, your audience, and the goal (promotional, informational, transactional, re-engagement). Provide any brand voice guidelines or words to avoid. Ask for multiple variations to A/B test.

Examples

• "Generate 10 subject line variations for a 30% off summer sale email to existing customers"
• "Create subject lines for a B2B webinar invitation about data security trends"
• "Write re-engagement subject lines for subscribers who haven't opened emails in 90 days"

Guidelines

• Keep subject lines under 50 characters for full mobile display; 30-40 characters is optimal
• Use numbers, questions, or brackets [NEW] to stand out in crowded inboxes
• Avoid all-caps, excessive punctuation, and spam trigger words like FREE!!!, Act Now, or Limited Time
• Pair each subject line with optimized preview text that complements rather than repeats the subject
• Create variations using different psychological triggers: curiosity, urgency, social proof, and exclusivity