How do I actually test a subject line before sending?

How do I actually test a subject line before sending?

A subject line is the one sentence people see in their inbox. Testing it means trying two versions and letting a small group pick the winner. Most tools call this an A/B test.

Run it like this:
—
1. Write two subject lines that say the same thing differently. Example: a question vs. a number.
—
2. Send each version to 10% of your list (so 5% gets A, 5% gets B).
—
3. Wait 2-4 hours, then send the higher-opening winner to everyone else.

✅ Change only the subject between A and B. Keep everything else identical.

Homework: Write two subject lines for your next email. Just two.

New here? Start with the basics above.