10 Cold Email Subject Lines That Actually Get Opened

# 10 Cold Email Subject Lines That Actually Get Opened

Your subject line is the most important part of your cold email. If it doesn't get opened, nothing else matters.

After testing hundreds of subject lines, here are the 10 that consistently get the highest open rates.

Why Subject Lines Matter

64% of people say they open an email because of the subject line. That means your subject line is doing 80% of the work.

A great subject line gets opened. A bad one gets deleted — or worse, marked as spam.

The 10 Best Cold Email Subject Lines

1. "Quick question about [specific topic]"

Example: "Quick question about your onboarding flow"

Why it works: It's specific, it's humble, and it implies you have a real question (not a sales pitch).

2. "Saw your post about [topic]"

Example: "Saw your post about AI in sales"

Why it works: It shows you've done your research. It's personal. It implies you're not spamming everyone.

3. "Ideas for [specific problem]"

Example: "Ideas for reducing customer churn"

Why it works: It's solution-oriented. It promises value, not a pitch.

4. "[First Name] — quick thought"

Example: "Sarah — quick thought"

Why it works: It's casual. It feels like a friend sending you a message, not a sales email.

5. "Following up on [specific thing]"

Example: "Following up on your Product Hunt launch"

Why it works: It references something specific. It gives you a reason to follow up.

6. "Loved your recent [content type]"

Example: "Loved your recent blog post on cold email"

Why it works: It starts with a compliment. It's personal. People love hearing good things about their work.

7. "Question about [their product/service]"

Example: "Question about your analytics dashboard"

Why it works: It positions you as a potential customer. It's low-pressure.

8. "[Mutual connection] suggested I reach out"

Example: "John suggested I reach out"

Why it works: Social proof. It instantly builds trust. (Only use this if it's true!)

9. "Quick idea for [their company]"

Example: "Quick idea for Acme Corp"

Why it works: It promises value. It's short. It makes people curious.

10. "Just a quick one"

Example: "Just a quick one about your sales process"

Why it works: It's short. It implies the email won't be long. It lowers the barrier to opening.

Subject Lines to Avoid

These subject lines will get your email deleted or marked as spam:

• "Opportunity"
• "Partnership"
• "Following up" (without context)
• "Hello"
• "Quick question" (too generic)
• "Important"
• "Urgent"

How to Test Your Subject Lines

The best way to find what works for your audience is to test:

1. Send two versions of the same email with different subject lines 2. Track open rates 3. Double down on what works

With Copywise, you can automatically generate multiple subject line options and pick the best one.

[Try Copywise free →](https://copywise.vercel.app)

Final Tip

Keep it short. Most people check email on their phone, and long subject lines get cut off.

Aim for 6-10 words. That's long enough to be specific, short enough to be read on a phone.