📌AI Email Subject Line Generator

AI Email Subject Line Generator
— Write Subject Lines
That Get Opened

47% of people open emails based solely on the subject line. Generate 5+ high-performing subject line options for any email in seconds — with AI trained on what actually gets clicks.

Multiple variationsSpam-word freeFree to start
✓ No credit card required
Generated Subject Lines — Cold Sales Email
Quick question about Acme's Q3 pipelineCuriosity
How Nova cut deal cycles by 35% — relevant?Social Proof
[First Name] — 2 minutes to double your close rate?Personalized
Re: Your expansion into enterpriseRe: Hook
The #1 mistake SaaS teams make at your stageQuestion
5 subject line variations generated in 3 seconds

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50 Email Subject Line Examples

Copy a subject line as is, or use the generator above to adapt it to your email. Keep subject lines specific and, ideally, under about 50 characters so they aren't cut off on mobile.

Professional email subject lines

  • Question about invoice #4821
  • Meeting request: Q4 planning, Thursday?
  • Quick favor: can you review this by Friday?
  • Following up on our conversation
  • Update on the [project] timeline
  • Introduction: [Name], meet [Name]
  • Action needed: sign by [date]
  • Thank you for your help today

Cold email subject lines

  • Idea for [Company]'s onboarding
  • Quick question about [topic]
  • [Mutual contact] suggested I reach out
  • Congrats on [achievement], [Name]
  • A faster way to [outcome]
  • Noticed [Company] is hiring [role]
  • 15 minutes next week?
  • [Name], a thought on your [process]

Sales email subject lines

  • How [Customer] cut [cost] by 30%
  • Your demo of [Product]
  • Proposal for [Company]: [project]
  • Still interested in [goal]?
  • Last chance: pricing ends Friday
  • Next steps for [Company]
  • A quick case study for [industry]
  • Can we help with [problem]?

Follow-up email subject lines

  • Following up on [topic]
  • Re: [original subject]
  • Checking in on the proposal
  • Any questions on the [document]?
  • Just circling back
  • One more thing about [topic]
  • Thanks for meeting today: next steps
  • Reminder: [deadline] is approaching

Email marketing subject lines

  • Your free guide to [topic] is inside
  • New: [feature] is here
  • [Name], your weekly summary
  • 5 ways to [achieve result]
  • We saved you a spot
  • The [month] edition: what's new
  • Don't miss out: [offer] ends tonight
  • You asked, we built it

Thank you and relationship subject lines

  • Thank you for choosing [Company]
  • Thanks for your feedback
  • Great meeting you at [event]
  • We appreciate you, [Name]
  • Thank you for the introduction
  • Thank you for your time today
  • A note of thanks from [Name]
  • Your help meant a lot
  • Welcome aboard, [Name]!
  • Thanks again: here's what happens next
47%
of emails are opened or ignored based on the subject line alone
69%
of email recipients report email as spam based on the subject line
22%
higher open rates from personalized subject lines
50%
of emails are opened on mobile — keep subject lines short

Subject Lines for Every Email Type

From cold emails to newsletters — generate the right subject line for any campaign.

❄️

Cold Email

Curiosity-driven subject lines that stop the scroll and get cold emails opened.

🔄

Follow-Up

Follow-up subject lines that don't feel like nagging — they feel like value.

📊

Sales Email

Benefit-led subject lines that create urgency without clickbait.

📧

Newsletter

Engaging subject lines that boost open rates for weekly or monthly newsletters.

🎉

Promotional

Time-sensitive, offer-focused subject lines that drive clicks on promotional campaigns.

🤝

Networking

Warm, personal subject lines for introduction and networking emails.

6 Proven Subject Line Formulas

Our AI uses these battle-tested frameworks to generate subject lines that convert.

Curiosity Gap
"One thing I noticed about [Company]'s pricing"

Creates a gap between what they know and what they want to know.

Personalization
"Quick question, [First Name]"

Uses their name or company to create an immediate personal connection.

Direct Benefit
"How to cut your CAC by 30% in 60 days"

Leads with a specific, credible outcome the reader cares about.

Social Proof
"How [Competitor] uses [Product] to [Result]"

Leverages FOMO and industry relevance to earn the open.

Question Hook
"Are you making this email mistake?"

A direct question that makes the reader feel personally addressed.

Re: Thread
"Re: [Previous Email Topic]"

Mimics a reply thread — dramatically boosts open rates for follow-ups.

Subject Line Generator FAQs

Everything you need to know about writing email subject lines that get opened.

What makes a good email subject line?

Great subject lines are: specific (not vague), relevant to the recipient, under 50 characters (mobile-safe), and create either curiosity, urgency, or clear value. Avoid spam trigger words like 'FREE', 'URGENT', or excessive punctuation.

How long should an email subject line be?

Aim for 30–50 characters (4–7 words). Longer subject lines get cut off on mobile devices, where over 60% of emails are opened. Our AI generates mobile-optimized subject lines by default.

Do personalized subject lines improve open rates?

Yes — significantly. Personalized subject lines (with the recipient's name or company) increase open rates by 20–30% on average. Our AI generates personalized variations for every email type.

Should I use emojis in email subject lines?

Emojis can boost open rates in consumer/B2C emails by 15–20%. For B2B or formal contexts, avoid them. Our AI calibrates emoji use based on the email's purpose and audience.

What subject line words should I avoid?

Avoid spam trigger words: 'free', 'guarantee', 'no risk', 'act now', 'click here', 'limited time offer', and excessive exclamation marks. These hurt deliverability and get emails filtered to spam.

Is the subject line generator free?

Yes! EmailGen AI is free to start with no credit card required. Generate subject lines immediately. Pro plans unlock advanced AI models and higher monthly limits.

Stop Losing Emails to Ignored Subject Lines

Generate 5 subject line options for any email in seconds — free.

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