How It Works

See how easy Best Subject Line is to use!

Enter Your Subject Line

Simply type or paste your subject line into the input box and click the button to get your score.

Enter your subject line
Review your score

Review Your Score

We grade your subject line from 0-100 based on our top secret algorithm.

Review Our Suggestions

When you scroll down you'll see our suggestions for how to improve your subject line.

Review our suggestions
Get the right results

Update & Test Again

When you're done revising your subject line simply scroll to top and enter it to test it again. Keep repeating until you're happy with it!

Try out Best Subject Line today!