BenefitsWhy You'll Love This
Key advantages that make a real difference for your team
Instant Scoring
Get a score from 0-100 based on length, word choice, and spam risk.
Spam Trigger Detection
We flag words that trigger spam filters.
Score Your Subject Line Instantly
Get a breakdown in seconds: character count, personalization tokens, spam word flags, and an overall score.
- 0-100 scoring system
- Character and word count analysis
- Personalization token detection
- Emoji effectiveness check
Catch Spam Triggers Before Gmail Does
Scans for known spam triggers, capitalization issues, and formatting red flags.
ProcessHow It Works
Get started in just a few simple steps
Enter Your Subject Line
Paste or type it in.
Get Your Score
Instant analysis with overall score and breakdown.
Review Suggestions
See specific recommendations.
Optimize and Send
Apply suggestions, retest, and launch.
Use CasesWho Uses This
Perfect for teams and individuals across different roles
Email Marketers
Score every subject line before it goes out.
SDRs
Test cold email subjects first.
"Started testing every subject line. Our open rate went from 24% to 38% in a month."
Mia J.
Email Marketer
FAQFrequently Asked Questions
Common questions about Email Subject Line Tester
Yes. Free to use with no signup required.