Free tool · no signup
Email subject line generator: ten lines, ten reasons to open.
Half of your email's result is decided before anyone reads it. Describe what the email says or offers, who receives it and what kind of email it is, and the generator writes ten subject lines in ten approaches, each with a preview text that adds information instead of repeating the subject. All under 50 characters, no spam triggers, no fake replies.
Your brief
Your subject lines
Ten subject lines with preview text appear here.
Keep these results and generate more
Enter your work email: we save your inputs and results so you can print them or keep them as a PDF, and every generator stays unlocked on this device. No newsletter.
By saving, you agree to our privacy policy Privacy.
Embed this tool
Paste this on your own site. It links back here, which keeps the tool up to date.
<iframe src="https://aistrikeforce.com/tools/email-subject-line-generator?embed=1" title="Email subject line generator" width="100%" height="860" style="border:0;border-radius:24px" loading="lazy"></iframe> <p><a href="https://aistrikeforce.com/tools/email-subject-line-generator">Email subject line generator</a> by AI Strike Force</p>
Want the follow-up to send itself?
We build the sequences behind the subject line: automatic follow-ups, reminders and lead scoring in your CRM, so a reply turns into a booked call without anyone chasing.
How the subject line generator works
A subject line earns the open and the preview text finishes the thought, so the generator writes them as a pair. It uses ten approaches (a plain benefit, curiosity, a question, a number, urgency that is true, a personal line, a story, a how-to, social proof when you gave some, and a very short line), keeps every subject under 50 characters so it survives a phone screen, and avoids the words and punctuation that spam filters and readers both dislike.
How to get more opens
- Be specific about the content: "3 automations that saved a clinic 20 hours" beats "Our October news".
- Use the preview text. Many senders leave it to the first line of the email, which is often "View in browser".
- Test two subject lines on 20 percent of the list, then send the winner to the rest; most email tools do this in one click.
- Urgency only when it is real. A deadline that moves every week trains people to ignore you.
- For cold outreach, keep it short and plain, and mention their context, not your product.
- Keep the follow-up subject different from the first email; "Re:" on a message that is not a reply reads as a trick.
Example
Questions, answered.
Is it free?
Yes. The first run on each generator is free without any signup. After that we ask for a work email, which keeps bots from draining the generators and lets you keep your results. No newsletter.
How long should a subject line be?
Under 50 characters, and the first 35 should carry the point, because phones cut the rest. The preview text can add 40 to 90 characters more.
What is preview text?
The grey line after the subject in the inbox. If you do not set it, the email client takes the first text of the email. Set it to add the second half of the thought.
Does it help with cold email?
Choose "Cold outreach". The subject lines come out short, plain and about the recipient, without the tricks that get cold email marked as spam.
Will these subject lines land in spam?
Spam filters look at the sender's reputation and the whole email more than the subject, but the generator avoids the known triggers: all caps, stacked exclamation marks, money symbols, fake replies and "free" with urgency.
Can it write in French, Spanish, German or Arabic?
Yes. Choose the output language in the form: English, French, Spanish, German, Arabic, Portuguese, Italian or Dutch. The generator writes natively in that language rather than translating an English draft.
What do you do with what I type?
Your inputs go to the AI model that writes the result and come back to your browser; we do not store them. If you save a report, we keep your email with the inputs and results so you can find them again, and nothing else.
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