Free Email Marketing Tool
Email Subject Line Tester
Test email subject lines for length, spam triggers, readability, personalization, emoji balance, and mobile inbox preview.
Privacy: Your subject lines are analyzed locally in your browser. Nothing is uploaded.
Score
0
Characters
0
Words
0
Spam words
0
Emoji
0
Grade
-
1. Write Your Subject Line
Add optional preview text to see how it may appear in an inbox.
Inbox Preview
Desktop preview
Your subject line will appear here
Preview text will appear here
Mobile preview
Your subject line will appear here
Preview text will appear here
Recommended Length
- Subject: 30–50 characters is often safer for mobile.
- Preview text: 40–90 characters is usually practical.
- Avoid excessive punctuation and all-caps words.
Analysis Report
0
Subject Score
Enter a subject line to get recommendations.
Spam Trigger Detector
Detected risky words or patterns will appear here.
No spam triggers detected yet.
Improved Subject Suggestions
About Email Subject Line Tester
Email Subject Line Tester helps email marketers improve campaign open rates by checking subject length, spam-heavy language, personalization, clarity, urgency, emoji balance, and inbox preview quality.
Common use cases
- Improve newsletter and promotional email subject lines.
- Reduce spammy words before campaign sending.
- Preview how subject and preheader text may look in inboxes.
- Create cleaner alternatives for A/B testing.