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Subject Line Tester
Use when you have an email ready to send but are unsure whether the subject line will get it opened.
Primitive: one copy-paste step. Combine it with other skills in a workflow for a full run.
After pasting into your AI tool, replace the [BRACKETED PLACEHOLDERS] with your own details.
The Skill
Review this email subject line and suggest better alternatives. Recipient type: [COLD PROSPECT / EXISTING CLIENT / NEWSLETTER SUBSCRIBER / OTHER] Email topic: [WHAT THE EMAIL IS ABOUT IN ONE SENTENCE] Current subject line: [YOUR CURRENT SUBJECT LINE] For each alternative: - Write the subject line - Explain in one sentence why it would perform better - Rate it: curiosity (1–5), specificity (1–5), low-threat feel (1–5) Then pick the single best option and explain your choice. Keep all subject lines under 50 characters. No clickbait, no ALL CAPS.
Example output
Your subject: "Following up on our conversation" — Score: 4/10 (generic, no reason to open) Alternatives: 1. "One thing I noticed on your site" — specific, intriguing — 8/10 2. "Quick question about [their company]" — curiosity, low threat — 7/10 3. "Saw your post on X" — personal, timely — 7/10 Best pick: #1 for cold outreach. #2 if you've had previous contact.