SlickCalcs

Email Subject Lines Prompt: 30 Options

This email subject lines prompt generates 30 open-worthy subjects across proven copy frameworks. Enter the email topic, paste into any AI tool.

The prompt

Role:
Act as an email copywriter obsessed with open rates.

Context:
Email topic: [EMAIL_TOPIC]. Audience: [AUDIENCE]. Email type: [EMAIL_TYPE] (newsletter, promo, onboarding, re-engagement). Tone: [TONE].

Task:
1. Generate 30 subject lines across 6 frameworks (5 each): curiosity, benefit, urgency, social proof, question, personal.
2. Keep each under 50 characters; show the count after each line.
3. Write 5 matching preview-text lines (under 90 characters) for the top 5 subjects.
4. Rank the top 5 by predicted open rate, with a one-line reason each.
5. Flag any line likely to trigger spam filters and provide a safer rewrite.
6. Suggest which 2 to A/B test first and the success metric.

Format:
- Grouped by framework, with character counts
- Top 5 with preview text
- Spam-risk flags with rewrites
- A/B test recommendation

Constraints:
- No ALL CAPS, no excessive punctuation (!!!), no misleading RE:/Fwd:.
- Avoid spam-trigger words: free, guaranteed, act now, no cost.
- Each subject must be truthful about the email content.
- Preview text must complement, not repeat, the subject.

Variables to fill in

Replace each [variable] in the prompt with your own details:

[EMAIL_TOPIC] [AUDIENCE] [EMAIL_TYPE] [TONE]

Example input

EMAIL_TOPIC: new budget templates release; AUDIENCE: newsletter subscribers interested in personal finance; EMAIL_TYPE: newsletter; TONE: friendly

How to use this prompt

Copy the prompt. Fill in the email topic and type. Paste into any AI tool, then A/B test the top 2 subjects on 10% of the list each.

Tips for the best results

Tip: Test subject lines on small segments before the full send — winners vary by audience.
Tip: Preview text is a second subject line; never leave it as default filler text.
Tip: Keep a swipe file of winning subjects to feed back into future runs.