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Free Email Subject Line Generator

A subject line earns the open by being specific, not by being clever. Every set is written to 28–50 characters, scored, and previewed before you choose one.

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Let’s name it!

Describe the piece, or paste it in full. Set a primary keyword under Details and every headline will carry it — and the score will start measuring where it sits.

Generated headlines
Your headlines will appear herePick what the headline is for, say what the piece is about, then press Generate. Every headline comes back editable, counted against its own limit, scored, and previewed where it will appear.
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Headline details

Optional. Everything here is kept between runs, so set it once.

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Email subject line generator

When you need a email subject

The email is written and the subject line decides whether it is read. You want several to choose from, and you want to see how each one looks in a phone inbox before you send.

What a email subject has to do

A subject line earns the open by being specific, not by being clever. It fits the roughly 38 characters a phone shows, it says what the email is about, and it is followed by preview text that continues the thought instead of repeating it.

  • The point in the first 38 charactersThat is what a phone inbox shows. Everything after it is a bonus, not a plan.
  • Specific beats clever"Your March invoice is ready" outperforms "A little something for you" every time, because the reader knows what they are opening.
  • Preview text is the second lineMost clients show 40 to 90 characters after the subject. Repeating the subject there wastes the only other line you get.
  • No manufactured urgency"Last chance" on an email with no deadline trains the reader to ignore the next one that has a real one.
  • No spam triggersAll capitals, rows of exclamation marks, "FREE!!", a fake "Re:" — each one costs deliverability as well as trust.

How to use the email subject line generator

Three steps, and the third is where the choosing happens.

1

Say what it is about

Two or three lines about the piece — what it covers, who it is for, and the one thing the headline should promise. Or paste the finished draft and let it be titled from that.

2

Check the settings

Email subject line is already selected on this page, so the 28–50 character range and its rules are set. Choose how many headlines to see, the angles you want, and add a primary keyword under Details if the piece is targeting one.

3

Compare and edit

Every headline arrives with its character count, its score and its angle. Edit any of them in place and the numbers move with you, and the preview shows the selected one in a phone inbox row.

Generate email subject headlines

The numbers this page holds you to

Every headline is counted against these, and anything past the hard limit is rewritten before you see it.

  • Written to28–50 characters, 3–9 words.
  • Hard limit78 characters. A headline longer than this is rejected and rewritten rather than trimmed mid-word.
  • Cut at about38 characters, which is what a phone inbox row actually shows. The preview draws the cut so you can see it.
  • ScoreOut of 100, measured against this purpose's own range rather than a generic ideal.

Common mistakes

Three ways a email subject goes wrong, all of them visible in the score.

Too long, or the wrong shape

A subject line that is the whole email, so there is no reason to open it.

Vague where it should be specific

The company name first, when the reader already sees the sender.

Written for the writer, not the reader

Emoji as the first character, which some clients render as a box and some strip entirely.

Email subject line generator FAQs

Is the email subject line generator free?

Yes. Every purpose, angle, tone and count is free, without an account, within the per-request word allowance shown next to the brief. Signing in raises the allowance and Pro removes the guest limits and the ads — no feature of the email subject line generator is held back on any plan.

What is the best length for an email subject line?

Between 28 and 50 characters. Phones show roughly 38 before cutting, and desktop clients show 60 to 70, so a subject that reads completely at 38 works everywhere. The preview on this page draws a phone inbox row so you can see exactly where yours is cut.

Does it write the preview text too?

Yes. Every subject line comes back with matching preheader text of 40 to 90 characters that continues the subject rather than repeating it, and the inbox preview shows the two together the way the reader will see them.

Can it write the email as well?

The Email Writer takes the same situation and writes the whole message — subject line, body and sign-off — in fifteen purposes from a reply to a resignation. Use this page when the body already exists and only the subject is still open.

How is each headline scored?

Out of 100, across five bands you can open and read on every card: length against the 28–50 character range for this purpose (25 points), how much of the wording carries meaning (20), clarity (20), keyword placement when you set a primary keyword (20), and specificity (15). The score runs in your browser and updates as you edit, and it measures the shape of the line — not a prediction of clicks, which nobody can make without your audience.

Will it keep the names and numbers in my brief?

Yes, exactly as you typed them. And it works the other way too: a headline containing a figure that could not have come from your brief is rejected before you ever see it, as are placeholders such as [Topic] or “Your Company”. Anything your brief does not state is treated as unavailable rather than invented.

Once the headline is chosen

Write the piece underneath it, check the grammar, or summarise a finished draft into the description that goes with it. One plan covers every tool.

AI writerGrammar checkerSummarizerAll thirteen purposes

One page per kind of headline

Each page opens the generator with that purpose already selected, and explains what that surface rewards, where it cuts a line, and what a headline written for it has to carry. The full picker, with all thirteen, is on the main headline generator.

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