Tips for writing open-worthy email subject lines (with examples)

A subject line is simple 30-character sentence that can determine whether your message gets opened or ignored. It is the first impression you make in your recipient’s inbox and has enough power to influence 47% of recipients and the success of your entire campaign. 

This is not meant to scare you, only motivate you to give it some thought. 

Email subject line best practices 

Determine your purpose

Before crafting your email subject lines, asses the purpose of your email. Are you aiming to promote a new service or product, share resources, or simply engage with your audience? 

Understanding what you want to accomplish will guide the tone, language, and structure of your subject lines. 

For example, if your goal is to boost sales, your subject line might focus on a special offer or discount. If you're looking to build community, your subject line might invite conversation or feedback. 

Understand your audience

Tailoring your subject lines to your audience's specific needs and characteristics Different audiences will respond to different styles; a lighthearted, witty subject line might work for a younger audience, while a more straightforward, professional tone may be better suited for a corporate demographic. 

Another route is to think about past email campaigns that have performed well. Asses what it was about that campaign that folks responded well to. Are there any patterns in the language you used and the language your audience uses? Go back to any feedback you received.

An understanding of your readers will enable you to create subject lines that feel personal and relevant, increasing the likelihood that they’ll open your emails!

When possible, personalize

According to Campaign Monitor, “personalized subject lines are 26% more likely to be opened.”  They help to create a sense of connection and relevance, which can significantly boost open rates. 

Personalization strategies include segmenting your audience and using data such as their name, company name, or their birthday

Examples of effective personalized subject lines:

• "[Name], here's a special offer just for you!"
• "We picked these [products/services] just for you, [Name]"
  “Your birthday’s coming up - treat yourself!” 

Keep it short

For email subject lines, brevity is your friend. The ideal length is 6-10 words or around 40-60 characters. This standard length ensures that your subject line is visible on most devices, especially mobile, where space is limited. 

Short, impactful subject lines are more likely to catch the reader's eye and convey the essence of your message quickly.

Tips for writing short and impactful subject lines:

• Focus on the core message you want to deliver.
• Use strong, direct language that gets to the point.
• Avoid unnecessary words or filler phrases.

Focus on the action

Incorporating action-oriented language in your subject lines communicates the goal of the email and sets the tone for the action you want them to take. 

Action-oriented subject lines create a sense of dynamism and urgency, which can lead to higher open rates.

Examples of action-oriented subject lines:

• "Get Started on Your Wellness Journey"
• "Claim Your Free Guide Now"
• "Join Us for an Exclusive Webinar"

These subject lines use verbs like "get," "claim," and "join" to prompt immediate action from the reader.

Avoid spam triggers

There is a fine line between being “action-oriented” and being spammy. 

Spam filters protect users from unwanted and potentially harmful emails, but if you're not careful, they can also mistakenly block your legitimate marketing emails. 

Tips to ensure deliverability:

• Use natural language and avoid over-the-top claims.
• Personalize your emails to increase relevance.
• Test your emails through spam filter tools before sending them.

Common spam trigger words and phrases include "free," "win," "urgent," and "guaranteed."Avoid using these trigger words excessively and be mindful of other spam triggers, such as using too many exclamation points or all caps.

How to use exclamation points and all caps properly

While exclamation points and all caps can add emphasis, overusing them can get spammy and to-be-honest a little annoying. 

Use punctuation and capitalization strategically to convey excitement or urgency without overwhelming the reader. 

Examples of effective subject lines:

• "Don’t Miss Our Biggest Sale Yet!"
• "Ready for Your Next Adventure? Pack Your Bags!"

Add emojis and symbols

According to Experian, subject lines with emojis can increase open rates by as much as 56%. However, they should be used thoughtfully and sparingly to avoid appearing gimmicky. 

When and how to use emojis effectively:

• Use emojis that are relevant to the content of your email.
• Place emojis at the beginning or end of your subject line to draw attention.
• Avoid overloading your subject line with multiple emojis.

Strategies for writing open-worthy email subject lines to use 

1. Peak their curiosity 

Best for: Pre-launches, sneak-peaks, and promotions.

When your subject line hints at something intriguing but leaves out key details, it encourages the recipient to click through to satisfy their curiosity. You want to reveal just enough to spark interest without giving everything away.

Successful curiosity-inducing subject lines:

• "You won't believe what’s coming next..."
• "The secret to [desired outcome] revealed inside"
• "Discover the hidden benefits of [product/service]"
  

What to avoid: Not providing the answer to your subject line within the email.

2. Poke the bear with controversy 

Best for: Light-hearted campaigns

Controversial subject lines are compelling because they challenge the status quo or provoke thought. But it can be a bold move and requires careful consideration. 

Ensure the “controversy” relates to your brand, audience, and your email. Draw the line and avoid topics that may alienate or offend your audience. The goal is to spark interest and conversation, not to create discord.

Some not-so-hot takes include: 

• "It’s okay to not wash your legs every day"
• "Mondays don’t actually suck "

What to avoid: Sensitive topics that could damage your brand's reputation. 

3. Provide value using data and numbers 

Best for: Educational emails, how-to content

Incorporating compelling statistics into your subject lines can grab attention by offering concrete, intriguing information. 

Examples of statistical subject lines:

• "Increase your sales by 30% with this simple strategy"
• "9 out of 10 professionals are using this tool—are you?"

Additionally, people are naturally drawn to numbers because they promise specific insights or value. Using numbers in subject lines sets clear expectations and makes your content feel more digestible.

Examples of numerical subject lines:

• "5 Tips to Boost Your Productivity Today"
• "Top 10 Destinations for Your Next Vacation"

What to avoid: Not sharing what was promised in your email.

4. Share a story 

Best for: Inspirational content, how-to, testimonials

Storytelling in subject lines can draw readers in by hinting at a narrative they want to explore further. The goal is to present a small snippet that promises more within the email.

Examples of storytelling subject lines:

• "From struggle to success: How one entrepreneur made it"
• "It’s time to take you back to where this all started."

What to avoid: An email can only contain so much. Don’t forget to offer a way for the reader to learn more about the story! 

5. Make them laugh 

Best for: Product promotions, seasonal campaigns 

Humor can be a powerful way to grab your reader's attention - after all, isn’t the way to a person’s heart through laughter? 

When using humor, it’s important to ensure that it aligns with your brand voice and that the joke is universally understandable. Humorous subject lines often use wordplay, puns, or lighthearted commentary to grab attention.

Examples of successful humorous subject lines:

• "We can’t be-leaf it's already fall!"
• "Time flies when you’re having rum! (But seriously, it’s on sale)"
• "Dad jokes? We've got those—and a Father’s Day sale too!"
• "Lettuce tell you about our new salad recipes"

What to avoid: Sharing a joke that’s too niche to a generation or geographical location (if your audience is worldwide) 

6. Pose a question

Best for: Promotions, educational content, survey requests

Posing a question in your subject line is a great way to engage your readers and prompt them to open the email to find the answer. Questions stimulate curiosity and create a sense of dialogue between you and the recipient.

Examples of question-based subject lines:

• "Are you making these common mistakes?"
• "What's your biggest challenge in [industry]?"
• "Grill and Chill: Memorial Day Deals You Can't Miss!"

What to avoid: Asking questions that may cause an existential crisis 

7. Celebrate the season

Best for: Promotions, seasonal campaigns

Making your subject lines relevant to your audience and timely in context can greatly enhance their effectiveness. 

Seasonal and event-based subject lines, like Black Friday, tap into what’s currently on the minds of your recipients, making your emails more appealing. For example, a subject line like "Get ready for summer with our must-have gear" resonates during the lead-up to the summer months.

Examples of effective subject lines:

• "Kickstart your New Year with these wellness tips"
• "Celebrate the season with our holiday specials"

What to avoid: Making generalizations about what holidays folks are celebrating. For example, use “Happy Holidays” vs. “Merry Christmas.” 

8. Tap into the FOMO 

Best for: promotions 

Creating a sense of urgency in your email subject lines can drive recipients to take immediate action, increasing open rates. As part of email subject line best practices, techniques to instill urgency include using time-sensitive language, such as "limited time offer" or "last chance." 

Examples of urgent subject lines:

• "Only a few seats left for our webinar!"
• "Last day to claim your discount!"

What to avoid: Sounding too sales-y.

Tips & tools for writing and testing your email subject lines

Analyzing the performance of your email subject lines is an important step to ensure the continuous success of your campaigns. 

You can use your sending platform’s analytics to help you gather valuable data on open rates, click-through rates, and overall engagement. Be sure to regularly monitor your campaign performance metrics to identify trends and use this knowledge to adjust your approach. 

Free subject line testing tools

Aside from your email sending platform, there are several free tools available to help you test the effectiveness of your subject lines before you hit send. 

These tools analyze your subject lines for factors like length, tone, and the likelihood of being marked as spam, providing insights and suggestions for improvement.

Overview of popular tools:

• CoSchedule Headline Analyzer: Evaluate the structure, grammar, and readability of your subject lines.
• Send Check It: Scores your subject lines based on spam triggers, length, and sentiment.
• SubjectLine.com: Offers a detailed analysis and suggestions for enhancing your subject lines.

Once you’ve tested your subject line using one of these tools, be sure to make adjustments and re-test!

A/B Test

By testing different versions of a subject line, you can determine which one resonates most with your audience and drives the best results. A/B testing allows you to experiment with different words, lengths, and tones to find the most effective combination.

Final tip 

By applying the strategies outlined in this guide—whether it’s creating urgency, injecting humor, or personalizing your approach—you can transform your subject lines from mundane to magnetic.

But remember, the best subject lines are those that resonate with your audience, reflect your brand's voice, and compel readers to take action. 

With continuous testing, thoughtful analysis, and a touch of creativity, you'll be well on your way to writing subject lines that not only capture attention but also drive the results you're aiming for.