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Email Subject Line Tester
Type a subject line to get a 0–100 score and concrete improvements.
Email Subject Line Tester
Subject line scoreStrong
| Check | Result |
|---|---|
| Length | 45 characters — good |
| Words | 7 words |
| Spam triggers | None found |
| Specificity | Contains a number — specific subjects tend to stand out |
Heuristics only — always A/B test with your own audience. Pair the subject with a preview text that adds information instead of repeating it.
Frequently asked questions
Is my data uploaded?
No. The calculation runs entirely in your browser — nothing you type is sent to a server.
Is it free?
Yes — free, unlimited and no sign-up.