Email A/B testing sends two versions to small groups and the better one to the rest. Over time, small improvements add up.
What to test
- Subject lines: question vs statement, with or without numbers. Check ideas with our subject line checker.
- Sender name: brand vs person.
- Offer: discount vs free gift.
- Call to action: wording and placement.
- Length: short vs long.
- Design: plain vs designed.
- Send time.
Running tests
- Test one thing at a time.
- Choose the success measure: clicks or conversions are better than opens.
- Split groups randomly.
- Use big enough groups; tiny lists produce unreliable results.
Small lists
If your list is small, test across several campaigns and look for consistent patterns rather than single winners.
Check significance
Use our A/B test calculator to see whether a difference is meaningful.
Keep a log
Record what you tested and learned.
Read A/B testing for beginners.
Want the full picture? This article is part of Email marketing: the complete guide, our in-depth guide with everything in one place.
