Cold Email Subject Line Scorer
Test your subject lines before sending. Get instant feedback on length, personalization, urgency, and spam risk.
Subject line scorer
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Subject Line Best Practices
What it does
Scores your email subject line on multiple factors: length, personalization, numbers, questions, spam words, and emoji. Provides instant feedback and an A-F grade.
Why it matters
Subject line is the most important factor in open rate. A great subject line can increase opens by 50%+ while a poor one kills campaigns before they start.
Definition
Score is calculated from: length (40-60 chars = +20pts), personalization (+15), numbers (+10), questions (+10), all-caps (-15 per occurrence), spam words (-20 each), emoji (+5).
Assumptions
- •Scoring is based on SaaS/B2B cold email best practices.
- •Personalization placeholders like {name} are recognized as high-value.
How to interpret your results
A grade (90+) = high open rate. B (80-89) = good. C (70-79) = acceptable. D (60-69) = below average. F (<60) = rewrite before sending.
How to improve
Use personalization
Add {name}, {company}, or {title} for 15-25% higher open rates. People open mail with their name in it.
Keep it short
40-60 characters fits mobile phones without truncation. Mobile opens are 60%+ of all email opens.
Add curiosity
Ask a question or include a number. Both trigger higher open rates than statements.
Avoid spam triggers
Words like 'free', 'guaranteed', 'urgent', and 'click here' lower open rates and increase spam folder placement.