Email Subject Line Analyzer

Analyze and score your email subject lines. Check length, spam words, emotional tone, and preview how subjects appear on mobile devices.

Frequently Asked Questions

What makes a good email subject line?
A good subject line is 30-50 characters, creates curiosity or urgency, avoids spam trigger words, and clearly communicates the value of opening the email. This tool scores all these factors.
What are spam trigger words?
Spam trigger words like "free," "guaranteed," "act now," and "limited time" can cause email filters to send your message to spam. This tool identifies these words so you can rephrase them.
How long should an email subject line be?
Keep subject lines under 50 characters for desktop and under 35 characters for mobile. About 46% of emails are opened on mobile, where long subjects get cut off.
Is my email content stored?
No. All analysis happens entirely in your browser. No email content is ever sent to a server.