Subject line tester

Check subject length, prefixes and promotional wording.

Your inputs

Paste your draft subject.

Your inputs stay in this browser. No account needed.

Your result

Add your inputs, or try the example, to see your result here.

Open rates cannot be predicted from a subject line alone.

How to use this tool

  1. Counts characters and applies transparent writing checks.

What the result tells you

  • Open rates cannot be predicted from a subject line alone.
Free Subject line tester | Terlido