Subject Line A/B Test Lab
For email marketers testing open-rate improvements with multiple subject line angles and preview text.
Best for these models
๐ The Prompt
๐ Prompt available in download
Get the full prompt text in a downloadable .txt file. Free, no signup required.
Download PromptVariables to fill in
{{CAMPAIGN_TYPE}} โ Replace with your input {{AUDIENCE}} โ Replace with your input {{TONE}} โ Replace with your input {{GOAL}} โ Replace with your input About this prompt
This template generates a set of subject line options for email campaigns and organizes them into useful test categories. It is designed for marketers who want to improve open rates without rewriting the whole email. The prompt asks the model to produce distinct angles, such as curiosity, urgency, benefit, and personalization, so testing becomes more strategic and less random.
It is ideal for teams running newsletters, promotions, welcome emails, or re-engagement campaigns that need a faster way to explore A/B testing ideas. The output can include preview text variations as well, which is important because the inbox preview often influences opens as much as the subject line itself. This makes the template valuable for both small teams and high-volume senders.
Customize it with audience details, offer type, tone, and key message. If you already know the campaign goal, include it so the model can match the subject line to the desired behavior. If you want stronger performance, ask for shorter options and fewer filler words. If your brand is playful, request more personality. This open-rate optimization workflow is best when you want fast options that are easy to test and compare.
Key features
- Creates multiple subject line angles quickly
- Organizes options into testable categories
- Adds matching preview text for each variation
- Improves A/B testing speed for email teams
- Supports newsletters, promos, and lifecycle emails
Best for
- โ Email marketers optimizing opens and clicks
- โ Growth teams running frequent inbox experiments
- โ Copywriters brainstorming campaign subject lines
Tips
- ๐ก Set {{GOAL}} to one action, like open, click, or reply.
- ๐ก Provide {{CAMPAIGN_TYPE}} so the tone matches the email type.
- ๐ก Ask for shorter options if your audience reads mostly on mobile.
What you'll get
A list of 12 subject line options grouped by angle, each with matching preview text and a note on when to use it. The output is easy to paste into an A/B test plan.
Preparing your download...
Download PromptRelated prompts
Abandoned Cart Recovery Copydoctor
For ecommerce teams recovering lost revenue with personalized cart reminder emails and incentives.
B2B Drip Sequence Nurture Planner
For B2B marketers building educational nurture sequences that progress leads toward a demo or trial.
Brand Voice Guide Constitution
For brand strategists defining a scalable voice system that writers can apply across channels.
Brand Voice Social Caption Matcher
For brand teams that need social captions aligned to strict voice guidelines across channels.