PromptWriting
Write email subject lines from the body
A prompt for writing eight email subject lines from the body, each 50 characters or under and spread across proven approaches.
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Your prompt
Write 8 subject lines for the email below. Every subject line must be 50 characters or fewer — count the characters and discard any that don't fit.
Cover a mix of approaches, labelled: direct/plain, curiosity gap, deadline/urgency, number-led, question, benefit-led, personalized-sounding, and one more of your choice. Every subject line must accurately reflect what's actually in the email — no promising content, urgency or a deadline the body doesn't contain. If the email has no real deadline, skip the deadline-based subject line rather than inventing one.
Email body:
Hi team, the new expense report tool goes live Monday. Please submit any pending reports in the old system by Friday, since it becomes read-only after that. A short walkthrough video is linked below.
Model-agnostic — works in Claude, ChatGPT, Gemini or any AI chat.
Why this prompt works
- →Stating the character limit as a rule to enforce, not a suggestion, is what keeps every line usable in a real inbox instead of truncating mid-word.
- →Labelling each approach turns the output into a genuine test set instead of eight lines that all lean on the same one trick.
- →Tying every subject line back to what the body actually says guards against the classic failure: urgency or a hook the email doesn't deliver on.