HOW TO TEST EMAIL SUBJECT LINES
Design a comparison you can interpret.
Fix the sender, preview text and email body. Choose one difference, such as specificity versus curiosity. Use a subscriber split test to measure actual opens and downstream actions.
Example messages.
A plumbing company emails past customers a $79 water heater flush, available through October 31; sender, preview text and body stay fixed.
$79 water heater flush through Oct 31
When did you last drain your water heater?
Run a clear comparison.
Use the same audience and product facts for both versions. Choose a question before running: clarity, credibility, interest or preference.
Head-to-head mode shows both texts together. Independent mode scores each separately against the same scale, then compares the scores for each profile.
What the results mean.
A simulation is useful for preparation; email performance needs subscriber data and careful measurement.
The survey supplies observed profiles. AI generates the reactions to your text. The included records are unweighted, and the results are not responses collected from people.
Frequently asked questions
How do I start?
Try a free study or open Studio to choose your audience. Paste both texts, add relevant context and run the study.
What should I do with a close result?
Inspect individual responses and revise the contrast. Small score differences are not a significance test. Use real audience feedback or a live experiment to validate consequential decisions.