B2B Email Subject Line Generator

Generate high-converting email subject lines that get opened. Create 10 personalized, mobile-optimized variations for cold outreach, follow-ups, demos, and more.

Email Details

Increase Open Rates

Personalized, mobile-optimized subject lines perform significantly better in B2B email campaigns.

Avoid Spam Filters

Our AI avoids spam trigger words and follows deliverability best practices to reach the inbox.

A/B Test Ready

Get 10 variations per generation—perfect for split testing to find your highest-performing subject lines.

B2B Email Subject Line Best Practices

✅ Do This

  • Keep it under 60 characters for mobile
  • Use personalization ({FirstName}, {Company})
  • Focus on specific value or outcome
  • Include numbers/data when relevant
  • Create curiosity without clickbait
  • A/B test different approaches

❌ Avoid This

  • Spam trigger words (free, guarantee, click)
  • ALL CAPS or excessive punctuation!!!
  • Misleading or clickbait subject lines
  • Generic or vague messaging
  • Overly salesy or pushy language
  • Subject lines that don't match email content

B2B Email Subject Line Formulas That Work

Question Formula:

"Is {Company} ready for {outcome}?"

Social Proof Formula:

"{Similar company} increased {metric} by {%}"

Curiosity Gap Formula:

"The {adjective} way to {achieve goal}"

Urgency Formula:

"Last chance: {opportunity} ends {date}"

Mutual Connection Formula:

"Re: {Mutual connection} suggested I reach out"

Frequently Asked Questions

What makes a good B2B email subject line?

A strong B2B email subject line is concise (under 60 characters), personalized, focused on value, creates curiosity, and speaks directly to the recipient's pain points or goals. It should avoid spam triggers while using power words and specificity to stand out in crowded inboxes.

How long should B2B email subject lines be?

Aim for 40-60 characters or 6-10 words. Most mobile email clients display only 30-40 characters, so put the most important information first. Our generator optimizes for mobile viewing while maintaining impact.

Should I use personalization in subject lines?

Yes! Emails with personalized subject lines (using {FirstName}, {Company}, or role-specific references) consistently perform better in B2B campaigns. However, ensure personalization is accurate, incorrect personalization is worse than none.

What subject line formats work best for cold emails?

For cold B2B emails, use curiosity-driven approaches, mutual connections ("Re: [Topic]"), questions, social proof ("[Company] increased ROI by X%"), or specific value propositions. Avoid salesy language and focus on relevance to the recipient.

How do I test email subject lines?

Use A/B testing with your email platform, testing different angles (question vs. statement, urgency vs. curiosity, benefit-focused vs. problem-focused). Track open rates, click rates, and reply rates. Our generator provides multiple variations for testing.

What words should I avoid in B2B email subject lines?

Avoid spam triggers like "free," "guarantee," "click here," "buy now," excessive punctuation (!!!), all caps, and overly promotional language. Also avoid misleading subject lines that don't match email content, as this damages trust and deliverability.

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