Should I A/B test my subject line or my send time first?

Should I A/B test my subject line or my send time first?

An A/B test sends two versions to small groups to see which wins. You can test the subject line OR the time you hit send.

Why it matters: subject lines have the biggest impact on whether emails get opened, so testing them pays off fastest.

— Step 1: Just one test to run? Test the subject line — that's your biggest lever.
— Step 2: Already winning at subjects? Then experiment with send times.
— Step 3: ✅ Only change ONE thing per test, or you won't know what actually worked.

Homework: write two subject lines for your next email and let your tool pick the winner.

New here? Start with the basics above.