Email Subject Line Generator
Generate high-converting email subject lines in seconds. Choose your tone, use case, and personalization level — get 5 ready-to-use subject lines instantly.
How to Write Email Subject Lines That Get Opened
Your email subject line is the single most important factor in determining whether your email gets opened. Studies show that 47% of recipients decide to open an email based solely on the subject line, while 69% report email as spam based on the subject line alone.
Best Practices for Email Subject Lines
- Keep it short: 6-10 words perform best. Mobile devices cut off after ~30 characters.
- Personalize: Subject lines with the recipient's name get 26% higher open rates.
- Create urgency: Time-sensitive language can boost open rates by 22%.
- Ask questions: Questions increase open rates by up to 10%.
- Avoid spam triggers: Words like "FREE", "BUY NOW", excessive caps, and multiple exclamation marks.
- A/B test: Always test 2-3 subject line variations per campaign.
Mobile Truncation & The "Preheader"
Over 60% of emails are opened on mobile devices first. The iPhone Mail app and Gmail mobile app will truncate subject lines after about 4-5 words (around 35-40 characters).
Using an email subject line generator helps you surface the most critical, personalized words at the very beginning. Furthermore, the preheader text (the first sentence of the email body displayed in the inbox preview) acts as a secondary subject line. Make sure your subject line and preheader work together perfectly to build curiosity.
Spam Filter Triggers
Your subject line is the first thing spam firewalls (like Google Workspace and Office 365) analyze. Avoid these critical mistakes:
- ALL CAPS: Never write your subject line in all capital letters.
- Excessive Punctuation: Avoid using multiple exclamation points (!!!) or question marks (???).
- Spam Words: Do not use highly promotional words like "Free", "Guarantee", "Risk-free", "Buy", "Promo", or "Cash".
- Bait and Switch: Using "Re:" or "Fwd:" when there was no previous conversation violates the CAN-SPAM act and leads to permanent domain blacklisting.
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