Let’s be real, no matter how good your email is, it means nothing if no one opens it.

Your subject line is the first impression. In a world where inboxes are flooded with promotions, newsletters, and notifications, standing out isn’t optional—it’s essential. Whether you’re running email campaigns for your brand or a client, knowing how to write high-converting subject lines can seriously change the game.

We’ll break down what makes a great subject line, how to increase email open rates in 2025, and the psychological triggers that actually get people to click.

 

Why Subject Lines Matter More Than Ever

The average person gets over 80 emails per day (Statista, 2024). Your message is just one of many fighting for attention. And with increasing use of mobile (around 70% of emails are opened on phones), your subject line needs to grab attention in less than 5 seconds.

A good subject line can yield higher open rates. It’s the difference between a dead email and a conversion opportunity.

So what makes a subject line work?

 

1. Keep It Short & Punchy

Short subject lines (under 40 characters) tend to perform better, especially on mobile.

Examples:

• “50% Off Ends Tonight”
• “Ready to grow your business?”
• “You forgot something…”

Why it works:

• Short = easy to scan
• Doesn’t get cut off on mobile
• Creates curiosity fast

Pro Tip: Use tools like CoSchedule’s Headline Analyzer or SubjectLine.com to test your subject lines before hitting send.

 

2. Add a Little Curiosity

Curiosity gets clicks. It makes people stop and think, “Wait… what is this?”

Examples:

• “This simple trick doubled our traffic”
• “You won’t believe what’s inside”
• “Guess what we’re launching tomorrow”

But be careful: clickbait works once—maybe. If your email doesn’t deliver, you’ll lose trust fast.

The balance: tease the benefit without giving away the whole story.

 

3. Use Numbers & Data

People are drawn to numbers—they feel specific, actionable, and legit.

Examples:

• “5 subject line hacks to boost open rates”
• “7 mistakes killing your email conversions”
• “$100k in 90 days: How we did it”

Why it works:

• Numbers break through visual noise
• They suggest the content is scannable
• They set expectations for the reader

SEO Tip: Include phrases like “email subject line tips,” “email open rate hacks,” and “how to increase email open rates” to boost search visibility.

 

4. Personalization = Higher Open Rates

Adding a name or a location can increase open rates by 26% (Campaign Monitor, 2024). People love seeing their own name or something tailored to them.

Examples:

• “Sarah, your free ebook is inside”
• “A special deal for Karachi”
• “Hey Ali, still interested in our service?”

Even if you don’t use the subscriber’s name, you can personalize based on:

• Recent behavior (clicked a link, visited a product)
• Time (e.g., “This weekend only”)
• Location or preferences

 

5. Use Emojis (But Not Too Many)

Emojis can increase open rates by up to 45% when used correctly.

Why? They grab attention and communicate tone quickly.

Examples:

• “Ready to grow faster?”
• “Your discount expires tonight”
• “Big news inside”

Tips:

• Stick to 1 emoji max
• Make sure it aligns with your brand
• Test across devices (some email clients don’t support all emojis)

 

6. Create Urgency (Without Being Pushy)

FOMO is real—and it works. Deadlines, limited offers, and exclusivity drive action.

Examples:

• “Last chance: Sale ends at midnight”
• “Only 24 hours left!”
• “Just 5 spots remaining…”

But don’t fake urgency. If every email is “urgent,” none are.

 

7. A/B Test Subject Lines

No one gets it perfect every time. That’s why smart marketers’ test.

What to A/B test:

• Short vs long subject lines
• With vs without emojis
• Question vs statement formats
• Including the recipient’s name vs generic

Even changing one word can make a difference. Tools like Mailchimp, Brevo, or ActiveCampaign make A/B testing super easy.

Real-World Example: BuzzFeed’s Email Game

BuzzFeed famously runs dozens of subject line tests before sending to their entire list. They test different tone styles (funny, shocking, emotional), and the one with the highest open rate wins. This approach helped them reach open rates which are above industry average.

Other great examples:

• Duolingo: “You’re losing your streak”
• Uber: “Your ride receipt + a surprise”
• Grammarly: “Your writing improved this week!”

These subject lines work because they’re short, relevant, and emotionally engaging.

 

Bonus Tips to Boost Open Rates

• Avoid spammy words: “Free!!!,” “Buy now,” “100% guaranteed” can trigger filters
• Use pre header text wisely: It acts like a second subject line
• Segment your list: Send relevant messages to specific groups
• Clean your email list regularly: Engaged lists = higher open rates

The secret to higher email open rates isn’t magic, it’s strategy.

Craft subject lines that are short, clear, and engaging. Test what works for your audience. Keep refining. The more value and clarity you offer upfront, the more likely people will click.