Email Subject Line Tester
Enter a subject line to get its score, a spam-risk check, and practical suggestions for a higher open rate. Preview how it will look in the inbox before sending your next email.
0/200 characters. Ideal length: 30-50 characters.
0
Length
-Words
-Spam risk
-Feedback
Preview (this is how it will look in the inbox)
From: your-company@example.com
The first line of this email will appear here in the preview...
How to use
- Enter your subject line.
- Press Test — see the score, spam risk and feedback.
- Edit as per the tips and test again.
Good to know
- Subject lines of 30 to 50 characters read well on mobile screens.
- Questions and numbers tend to draw more attention.
- Avoid clickbait — it hurts trust and future open rates.
- Test two versions on small batches and compare the results.
This score is an estimate based on common email marketing best practices — your actual open rate depends on your audience.
Frequently Asked Questions (FAQ)
What does the email subject line tester do?
You enter an email subject line and it gives a score, the spam risk and improvement tips so your open rate goes up.
Is the subject line tester free?
Yes. It is free, needs no signup and works instantly in your browser.
Is my subject line saved anywhere?
No. Everything runs in your browser and nothing is stored or uploaded.
Will a high score guarantee more opens?
No tool can guarantee open rates, but the tips help you write clearer, less spammy subject lines.