Free toolEmail and text
See your subject line in the inbox.
Type the sender name, the subject and the preview text. See them as one inbox row, the way a reader meets them, with the counts beside.
Runs in your browser. Nothing you type is sent to Runner.
- Subject characters
- 27
- Subject words
- 4
- Preview characters
- 63
- Emoji
- 1
- Words in capitals
- 0
- Exclamation marks
- 0
How it works
Type the name your email comes from and the subject line.
Add the preview text, the line most inboxes show after the subject.
Read the row as a customer would, and put the reason to open in the first few words.
Want this done for you, every week?
Runner gives growth a whole team: it finds the leads, sends each one your introduction, and drafts the posts and ads. You set the number it works toward.
Build my teamQuestions about the Email Subject Line Tester
How long should a subject line be?
Phone inboxes show roughly the first 30 to 40 characters and desktops more, depending on the app and the screen. Lead with the words that make someone open, so a cut costs nothing.
What is preview text?
The line an inbox shows after the subject, taken from the start of your email unless you set it. Most email tools have a preview text field; use it to finish the subject's thought.
Do capitals and exclamation marks hurt?
They make a line read as shouting, and filters weigh many signals, wording among them. This tester counts them so you can choose deliberately; it makes no promise about where an email lands.