Email Subject Line Generator and Optimizer

Generates 20 subject lines across 5 psychological categories, with a top-3 recommendation.

Best For

•An email marketer prepping a product launch send uses it to generate a real A/B test set across 5 psychological angles instead of guessing two variants
•A newsletter writer with declining open rates uses the curiosity-gap and question-format categories to break out of a stale pattern
•A growth marketer reporting on subject line performance uses the 'why it works' annotations to explain test results to stakeholders

Prompt Template

Generate 20 email subject lines for [EMAIL PURPOSE, newsletter issue / product launch / re-engagement / cold outreach]. Email content summary: [1–2 SENTENCE SUMMARY]. Audience: [AUDIENCE]. Goal metric: [OPEN RATE / REPLY RATE / CLICK RATE]. Deliver 4 subject lines in each of these 5 categories: (1) Curiosity gap ('You're making this mistake every day'), (2) Direct benefit ('Double your open rates in 7 days'), (3) Question format ('Are you leaving 40% of your revenue on the table?'), (4) Social proof ('How [NAME/BRAND] achieved [RESULT]'), (5) Urgency or scarcity. For each subject line, add a 'Why it works' annotation of one sentence. Flag your top 3 picks and explain why.

Pro Tip

Test winners against your own historical open-rate data rather than trusting the model's top-3 picks blindly, since subject line performance is highly audience-specific.

Example Output

A sample of what this prompt produces once you fill in the placeholders.

Curiosity: 'The metric everyone tracks wrong.' Direct benefit: 'Cut your reporting time by half this week.' Why it works: names a specific pain your audience already recognizes without revealing the answer.