Email Subject Line Tester
Test your email subject lines before you send. Get a 1-100 score with spam risk analysis, personalization check, and suggestions to improve open rates.
Frequently Asked Questions
What makes a good email subject line?
A good email subject line is 30-50 characters long, includes personalization (like 'you' or 'your'), contains 1-2 power words, avoids spam trigger words, and optionally uses one emoji. Subject lines that create curiosity or urgency tend to have higher open rates.
What are spam trigger words?
Spam trigger words are terms that email filters flag as potential spam. Examples include 'FREE', 'URGENT', 'ACT NOW', 'LIMITED TIME', 'CLICK HERE', 'BUY NOW', and 'GUARANTEED'. While using one sparingly may be okay, multiple spam words significantly increase the chance of landing in spam folders.
Should I use emojis in email subject lines?
One emoji can help your email stand out in a crowded inbox and slightly improve open rates. However, using 3 or more emojis looks spammy and can trigger spam filters. Use emojis sparingly and ensure they're relevant to your message.
How long should an email subject line be?
The optimal email subject line length is 30-50 characters. This ensures the full subject is visible on both desktop and mobile devices. Subject lines over 50 characters often get truncated on mobile, which can reduce open rates.
Does personalization improve email open rates?
Yes. Emails with personalized subject lines (using 'you', 'your', or the recipient's name) see 20-30% higher open rates on average. Even simple second-person language helps create a connection with the reader.