What the tester looks at
A subject line has a few seconds to earn a look. The tester checks the plain things that readers and inboxes react to.
- Length. Phones show far fewer letters than a desktop. Around 30 to 50 characters is easy to read everywhere.
- Words. Between 3 and 12 words can be taken in at a glance.
- Capital letters and exclamation marks. A subject in ALL CAPS reads like shouting.
- Emoji. One can stand out. Many look like an ad.
- Trigger words. Some phrases show up often in unwanted email, like "act now" or "100% free".
- Preview text. The line after the subject. It is free space many people leave empty.
How to use it
- Type or paste your subject line. The score updates as you type.
- Read the tips, from the top. Fix the red ones first.
- Check the three previews. If the main words are cut off, move them to the front.
- Write two or three versions and compare the scores. Then pick the one that sounds like you.
How the score works
The score starts at 100 and loses points for the things above, like a long subject, all capital letters, several exclamation marks or a trigger word. It is a guide to plain habits. It does not know your audience, and it cannot say how many people will open the email or where it will land. Your own results from past emails are a better judge, so keep the tester as a second pair of eyes.
Subject lines that work
- Say what is inside: "Your fall menu is here" beats "News".
- Use a real number when you have one: "3 new classes on Saturday".
- Write like a person: "Quick question about your order".
- Keep the main words in the first 30 characters.
- Do not promise what the email does not hold.
FAQ
How long should a subject line be?
Under 50 characters is a safe aim. Phones cut around 30 to 40 characters in a list, and a desktop shows about 60 to 70. Put the main words first and the rest will not matter if it is cut.
Do emoji help?
Sometimes they make a subject stand out in a full inbox. They can also look like an ad. Use one at most, at the end, and check how it shows on a phone.
Are spam trigger words a problem?
A single word does not send an email to spam. Inboxes look at who you are, how people react to your email and how your domain is set up. Still, a subject full of urgent promises looks like the unwanted kind to people too, so plainer words are a good habit.
Does the tester save my subject line?
No. It runs in your browser. Nothing you type is sent to Postfjord or saved, and the tool sets no cookies.
What is preview text?
The short line that mail apps show after the subject. If you leave it empty, the app shows the first words of the email, which are often "View in browser". Write a line that adds to the subject.