AI Email Subject Line Tester
Paste your subject line and get an honest 0–100 score with real deliverability checks: length, spam trigger words, ALL CAPS, excessive punctuation, emojis, personalization and preheader.
Check-by-check results
| Check | Your result | Status | Points |
|---|
Spam word scanner
The tool scanned your subject line against known spam trigger words.
3 concrete fixes
Frequently asked questions
What does the email subject line tester check?
It runs 9 real checks: character length, word count, spam trigger words, ALL CAPS ratio, excessive punctuation, emoji count, personalization tokens, question vs statement, and preheader length if you provide one.
What is the ideal email subject line length?
Between 30 and 50 characters with 5 to 9 words. This range displays fully on most phones and desktop inboxes without being cut off.
How does the score work?
Each check earns points up to a total of 100. Spam trigger words carry the biggest penalty because they can push your email into the spam folder. The tool also gives you 3 concrete fixes for your weakest checks.
Is my subject line uploaded anywhere?
No. The whole analysis runs in your browser. Nothing is sent to any server.