Paste the email, or describe it in a line or two. Hemmingway writes five subject lines to choose from, each saying what the email is about and what you need, in few enough words to read on a phone. You pick one and put it on your email yourself.
The subject lines come from your email and nothing else. It will not add a deadline you did not set, a discount you are not offering or a "Re:" to make it look like a reply.
What makes it work
- Say what it is and what you need. "Boiler broken since Monday: engineer date needed" can be dealt with from the inbox. "Hello" and "Quick question" cannot.
- Put the important words first. A phone shows the start of a subject line and cuts the rest. The date, the name or the request goes at the front.
- Make it match the email. A subject that promises more than the email delivers gets opened once.
- Write it last. Once the email is finished you know what it is about.
An example
Asked for subject lines for an email to a landlord about a boiler that has been broken since Monday, wanting a date for the engineer this week, polite but firm, subject lines along these lines are what to expect:
Boiler broken since Monday: engineer date needed
Broken boiler: please confirm an engineer this week
Boiler out since Monday, can you send someone this week?
Boiler repair: when can the engineer come?
Request: a date for the boiler repair this week
Pick the one that sounds like you.
Newsletters and emails to a list
The same form works for a newsletter, an offer or an event invitation: describe what is inside and who receives it. It is told not to write clickbait, capitals or false urgency.
If the email is not written yet, the AI email writer drafts it from a few notes, and there are separate tools for a cold email and a follow-up. For the line after the subject, see how to start an email.
Common questions
Is the email subject line generator free?
Yes. Hemmingway has a free trial with no card needed, and this tool opens it with your answers filled in. You sign up once, and the subject lines are written in the chat.
What makes a good email subject line?
It tells the reader what the email is about and what they need to do, before they open it. Specific beats clever: a name, a date or a request.
How long should an email subject line be?
About seven words, with the important ones first. A longer subject loses its ending on a phone.
Will it raise my open rate?
Nobody can promise that, and this tool does not. A clear, honest subject helps the right people open the email. How many do depends on your list and what you send.
Will it sound like AI?
It is built not to. Hemmingway-1, the model behind it, came first on sounding like a person in our own blind test, Human-Likeness. With a line this short the check takes a second: it should read like the top of an email from a person you know.