Last updated: March 2026
Frequently Asked Questions
Will this tell me my open rate?
No — actual open rates depend on your list, sender reputation, and send time. This tool catches subject-line issues that hurt open rates: spam triggers, length problems, low curiosity, all-caps shouting.
Does the score change based on B2B vs B2C?
The scoring is tuned for cold B2B outreach where emojis and urgency tactics hurt more. For B2C consumer emails, emojis and stronger urgency can work — use your judgment and A/B test in your ESP.
Can I use this for newsletter subject lines?
Yes. Newsletter subject lines benefit from the same rules: stay under 60 chars, avoid spam triggers, add curiosity. The tool works for any email context.