Email Subject Line: 20 Actionable Tips [Updated]

“Do not judge a book by its cover.”

Heard this phrase ever?

But when it comes to email marketing, people do judge an email by its subject line.

Most marketers make one common mistake: They think that subject line is just a small part of an email campaign.

The truth is: Subject line is the first thing that encourages your readers to read your email. It can make or break your email.

Here are some stats that show the importance of the subject line:

47% of marketers say they test different email subject lines to optimize their emails’ performance. (Hubspot)

47% of email recipients open an email based on the subject line whereas 69% of email recipients report email as spam based solely on the subject line (Invesp)

Want to boost your email’s engagement? 

It starts with a compelling subject line. An engaging subject line makes your email stand out in the crowded inbox.

How can I craft one? – You ask.

Don’t panic! I won’t leave you empty-handed. 🙂 

In this article, you’ll discover 20 subject line tips and real-life examples.

20 Subject Line Tips

1. Keep Your Subject Line Short and Concise

Try to keep your subject lines with 40 or fewer characters. Don’t use fluff words.

Your long subject lines will cut off on mobile devices (most smartphones only display five or six words of a subject line). 

75% of consumers say they use their smartphones most often to check email – That’s crazy! 

You can’t afford to miss this opportunity.

Here’s one email that I received from Lifehack:

Here are some other examples:

Barack Obama: “Hey”

Themeum: WP Page Builder Is Ready to Download

Paper.li: Email Marketing Daily Is Out!

Zomato: Your Order Is Being Processed!

2. Make It Personalized by using ‘Name’ or ‘You’

People love to see their name or something that wink their identity. Do you?

I believe you do.

Try to place recipient’s first name or the words like “you/your.” Give your subject line a personal touch.

According to MarketingSherpa, including a name in the subject line boosted open rates by 29.3%. 

Check out this email from Vyond. They used my name in the subject line.

3. Don’t Make False Promises

Don’t try to get your email opened by making false promises. You will lose your readers’ trust. Result?

Low open rate. High unsubscribe rate.

REPEAT after me: I’ll NEVER make false promises!

Always deliver what you promise in the subject line. 

4. What’s Inside? Tell them

Write a subject line that educates your subscribers. Tell them clearly what’s waiting inside the email.

Are you delivering an ebook via email?

Don’t just say, “Thank You.” 

Say, “Here’s your ebook.”

Here’s an email that I sent to my subscribers:

Here are some other examples:

Torrid: Inside: 60 seconds styling guide

Search Engine Journal: Get your guide to local SEO [EBOOK]

5. Use Magical Phrases to Make Them Feel Special

Use casual and friendly language in the subject line. Try the phrases that make your recipients feel special.

And… 

You’ll get magical results.

See this email subject line from Aweber. It contains the phrase “Your Private Invite.”

Here are some other examples:

MarketingProfs: An exclusive offer just for you

Purewow: Happy birthday! Here’s your special gift

6. “How to” Subject Line

‘How to” subject lines give a sense of valuable information to readers. It makes them feel that they’ll learn something (Benefit oriented).

Consider using the word “How to” in your subject line.

See how Ryan Robinson does this:

7. Create a Sense of Urgency

Humans have a deep fear of missing out on anything – Any event, any update, sale, offer, or opportunity).

It’s called FOMO (fear of missing out). 

So, create a sense of urgency in the subject line (hurry before it’s too late). These subject lines perform well.

Here are some other examples:

Shoeline.com: Summer closeout sale ends soon!

Fabric: Save up to 50% – 24 Hours Only

TOMS: For a limited time | SURPRISE SALE

8. Curiosity

The best subject line grabs the recipients’ attention, curiosity can help you do that.

How?

Make subscribers curious by leaving the subject line open-ended. Ask an interesting question, promise something, or say something unusual. And subscribers will open the email to fill the curiosity gap.

Check out this email subject line from Christian Mickelsen:

Take a look at some other examples:

Nearbuy.com: It’s time to break-up!

Brian Tracy: Do not do this (please)

G2Crowd.com: I got you a gift card

9. Add a Little Humor in Subject Line

Adding a little pun or humor is a great way to make your readers smile and spice up your subject line.

If you delight them, they will remember you. 

But don’t be offensive. Light humor will work for you.

Some of the best funny email subject lines come from Chubbies:

Here are more from them:

this tank top smells like pizza

ur the wurst

Let me pick your nose… er, I mean brain

sorry I’m late, traffic was horrible

10. Use Numbers/Lists

Adding numbers in your email subject line is a great way to get your email noticed and set an expectation.

Numbers and lists create curiosity and focus. This is one of the best practices for bloggers.

Take a look at these examples:

Ben Settle: 7 shameless email player rules.

Pinterest: 18 Ideas in home decor

11. Ask a Question

Asking a compelling question can pique readers’ curiosity. Keep your questions open-ended to entice the readers to find out the answer.

Check out this email I received:

12. Use Symbols or emojis in Subject Line

According to Experian, using emojis in your subject lines can increase your open rates by 45%.

Try out emojis and symbols into the subject line to make it more engaging. 

13. Subject line as CTA

What’s the job of your subject line?

Encourage people to open your message.

Make your subject line a Call-to-Action (CTA) that tells readers clearly what you want them to do.

Check out this subject line:

14. Use the word “Free”

Go to your inbox and check for subject lines contain the word “Free.”

Did you see a good number of emails?

Emails with the word “Free” in the subject line were opened 10% more than those without.

15. Retargeting Subject Line

Do you have subscribers who didn’t complete an action – Abandon their cart, or didn’t upgrade after free trial.

Retargeting subject lines (with a sweet deal) can bring them back to your sales process.

16. NEVER USE ALL CAPS

Don’t write your subject line in all caps. Why?

It sounds like you’re yelling at them. It looks spammy. I personally ignore these kinds of subject lines.

According to Radicati Group, 85% of respondents prefer an all-lowercase subject line. 

17. Compelling Preview Text

Preview text acts as an extension of your subject line. Preview text gives a teaser, so your audience knows what to expect from your email.

A Litmus survey found that 24% of respondents look at the preview text first when deciding to open an email.

Chubbies does a great job:

18. “The Lesson “ Subject Line

Is there some technique you tried and it got you success? Share your learnings and experience with your audience in email.

Use this formula to write the subject line:

[Number] Lessons [I/We] Learned by [Action You Took]

Check out this subject line:

19. Give Command

Give a clear command in your email subject line. It tells the readers exactly what you want them to do. So use some action verbs to encourage a response.

See this subject line from Zomato:

20. Use the Word “Video” In Subject Line

If you’re adding a video or podcast in your email body, make sure you’re telling people in your subject line, so they don’t miss out!

Check out this subject line:

Now It’s Your Turn

That’s it! Pat on your back. Now you’re an email subject line superhero. I hope you find these 20 best practices helpful in creating your next subject line.

Go ahead and start crafting your best subject line!