Business
Email Subject Line Tester
Privacy Verified
Score your email subject line for length, spam-trigger words, caps, punctuation and engagement signals, with a live inbox preview.
Your Name · Preview text appears here…
Mobile clients show ~30–40 characters; desktop ~60–70.
Scoring checks length, word count, spam-trigger words, ALL CAPS, excessive punctuation, personalization, numbers and urgency. Heuristics based on common email-marketing guidance — always A/B test with your real audience.
Privacy & Security
Runs entirely in your browser. No data is sent to any server.
Data: None
Client-side-Side
Active
v1.0
How to Use
Type your subject line to get an instant score out of 100 with specific fixes and a preview of how it truncates on mobile.
Disclaimer: This tool is provided "as is" without warranty of any kind. Results are for educational and utility purposes.