Email subject line tester
Type your email subject line to instantly see a score, the words spam filters don't like, tips and how the subject will look in the inbox.
A subject line people will open
- 1Type the subjectand the preheader, if any - the text after the subject
- 2See the scorefrom 0 to 100, plus a list of what to improve
- 3Check the previewhow the subject gets cut off on phone and desktop
How the score works
A subject starts with 100 points. Points are taken off for a subject that is too short or too long, words from spam filter lists, words in ALL CAPS, multiple exclamation marks, repeated symbols like "!!!" and "$$$", lots of emoji and fake "Re:" and "Fwd:". Numbers and personalization, on the other hand, add points. The score is a hint, not a verdict: the best way to test a subject is an A/B test on your own list.
Subject length
A phone shows about 35-40 characters of the subject, a desktop about 60. Anything beyond that is cut off with an ellipsis. So put the key point first and keep the subject to 25-45 characters. The preheader, the line after the subject, gives you more room: use it to add to the subject.
Spam words
The tool looks for typical marketing words in 10 languages: "free", "discount", "urgent", "you won", "gratis" and others. On their own they won't send an email to spam, but together with caps and exclamation marks they noticeably raise the risk. Found words are highlighted in the preview.
FAQ
Didn't find an answer? Message us and we'll help.
Usually 25-45 characters or 4-9 words. A subject like that is fully visible on a phone, where more than half of emails are opened. If the subject is longer, put the important part in the first 30-40 characters.
It's a short text the email client shows after the subject or below it. If you don't set it, the start of the email ends up there, often "View in browser". The preheader is set in your mailing settings.
One word, unlikely. Spam filters look at everything together: sender reputation, domain settings (SPF, DKIM, DMARC), complaints, the text itself. But a combo like "FREE!!! Today only" will almost certainly hurt.
One fitting emoji can make an email stand out in the inbox. Two or more already look like an ad, and some email clients show emoji differently or as a box.
Your email service has a merge field for this, such as {{name}}, *|FNAME|* or %name%. The tool recognizes these fields and counts them as personalization.
No. The check runs right in your browser, the subject and preheader never leave it.
Try also
Also free, no sign-up