How to Write Great Email Subject Lines (A Guide)

Your email subject line is the most important part of your email. It's the first impression, the gatekeeper that determines whether your message gets opened or sent straight to the trash. To help you craft compelling subject lines that demand attention, our free Email Subject Line Idea Generator can provide instant inspiration.

This guide covers the key principles of effective subject lines and how to generate dozens of ideas in seconds.

A free email subject line generator tool showing the topic 'Our new summer sale' and the tone 'Urgent', which has generated five time-sensitive subject line ideas.

Get instant, high-converting subject line ideas for any topic or tone.

What Makes a Subject Line Great?

The best subject lines leverage basic psychology to connect with the reader. Here are four proven elements to incorporate:

  • Benefit-Driven: Clearly state what the reader will gain by opening the email (e.g., "Save 50% on your next order").
  • Curiosity: Pique their interest without giving everything away (e.g., "The one mistake everyone makes...").
  • Urgency: Create a sense of FOMO (fear of missing out) to encourage immediate action (e.g., "Your offer expires tonight").
  • Personalization: Use the recipient's name or reference their past behavior to make the email feel more relevant.

How to Use the Subject Line Generator

Coming up with fresh ideas can be challenging. Our Subject Line Generator is a simple, browser-based tool that does the hard work for you.

  1. Enter Your Topic: Type in your product, offer, or the main theme of your email (e.g., "our new SEO course").
  2. Select a Tone: Choose from options like Urgent, Curious, or Benefit-Driven to match your campaign's goal.
  3. Click "Generate 5 Ideas": The tool will instantly provide a list of subject lines based on proven, high-performing templates.

Tips for Success

  • Keep it Short: Aim for under 50 characters to ensure your full subject line is visible on mobile devices.
  • Use Emojis Wisely: One or two relevant emojis can help your email stand out, but don't overdo it.
  • A/B Test Your Ideas: The only way to know what truly works for your audience is to test different subject lines and see which one gets more opens.

Stop guessing what works and start writing subject lines that get results. Try our free generator now and watch your open rates climb.