Email Subject Line Tester & Scorer
Analyze your subject line against spam filters and deliverability best practices. Get a real-time score with checklist to help you land in the inbox.
Expert Tip: What makes a good subject line?
Keep it between 3-15 words (under 60 characters), use one personalization token like {{first_name}}, and avoid spam-triggering words like 'Free' or 'Act Now' to ensure your email bypasses junk filters.
Enter an email subject line to start the deliverability analysis.
Tip: Personalize
Personalized subject lines increase open rates as much as 26%.
Tip: Mobile First
Keep it under 60 chars to avoid getting cut off on phones.
Tip: Be Honest
Avoid deceptive prefixes like "RE:" or "FWD:" to build trust.
Why Subject Line Analysis Matters
Your subject line determines both deliverability and open rates.
Bypass Spam Filters
Certain words and characters trigger modern email filters. Testing ensures your message reaches the primary inbox.
Optimize for Mobile
Over 50% of emails are read on mobile. We help you front-load your message so it doesn't get cut off.
"Your subject line is the single biggest factor in whether your email gets opened. Test once, send with confidence."
Frequently Asked Questions
Common questions about email deliverability and subject line optimization.
Add the Final Touch to Your Emails
A great subject line gets them in, a professional signature builds the trust. Create yours for free today.