Optimizing Your Email Subject Lines for Maximum Impact

Compelling email subject lines grab attention and increase engagement. Allow us to provide you with some subject line ideas, or explore our guide to craft your own.

Subject Line Generator for Emails

Select a keyword category (Benefit, Topic, or Pain-Point), input your keyword, and click "generate subject lines" to receive a list of ideas for your next compelling subject line!

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Write your own

What if you want to write your own email subject lines?

Our email subject line tool offers quick ideas for email subject lines using proven templates. However, if you desire more customization or wish to craft your own email subject lines, what should you do?

In other words…why do these subject line templates work?

During the development of this tool, we encountered numerous subject line templates that, while exceptionally effective, require further customization for your business and the specific email you’re sending. 

How to write great email subject lines

Why do people open emails?

  • They’re expecting your email (e.g. you’re delivering a lead magnet you promised them).
  • They trust and enjoy emails from you.
  • Your subject line promises them something they want.
  • Your subject line makes them so curious they have to click.

You build your reputation as a sender over time. You build trust with your readers by sending them great content that they love (and knowing).

Discover 5 research-backed ways to write mouthwatering subject lines (this bullet incorporates 3 of them).

Learn why selecting “weird words” can help people understand your emails better.

Explore another 11 email subject line templates that you can borrow and customize.

How to make people so curious they can’t not click

Are you familiar with the concept of an “information gap”? This notion was introduced in a 1994 paper by behavioral economist and Carnegie Mellon professor George Loewenstein.

Recent studies further endorse the idea that curiosity stems from a gap—the disparity between what you know and what you desire to know.

Skipping to the crux of the matter—17 pages into his paper, Loewenstein delineates five methods for inciting curiosity in others.

Here are the five ways you can spark curiosity in people:

1. Pose a curiosity-inducing question.
2. Initiate a sequence of events but leave it unfinished (e.g., an incomplete story).
3. Challenge expectations.
4. Suggest that you possess information they lack.
5. Suggest that they once knew something they’ve now forgotten.

In essence, this is all you require. Incorporate a few of these five methods into any subject line or headline, and you’ll pique people’s curiosity. Consider the following example:

Original: “How to earn half a million dollars a year”
Revised: “How can you earn half a million dollars a year?”
Even better: “Do you have the courage to earn half a million dollars a year?”

The first headline utilizes Method 4 (suggesting exclusive information), but it’s dull and somewhat dubious. The second headline employs Method 4 and Method 1 (posing a question), which improves it slightly. The third headline introduces an unexpected element (Method 3), questioning your courage. This is what makes it one of the most renowned ads of all time. For more examples of headlines/subject lines employing these five methods, look no further than Upworthy.

Upworthy has mastered the art of exploiting curiosity gaps. Their headlines commence stories, insinuate knowledge, and are unquestionably unexpected (e.g., “princess phase –> leadership skills?!”). Additionally, Upworthy’s stories are infused with emotion. Expressions like “and it’s perfection” or “gut-wrenching” evoke powerful emotions. Research by Jonah Berger reveals that emotional content is more likely to be shared, possibly because it motivates people to take action. Emotions play a well-documented role in decision-making, and although the desired action may be a “click” rather than a “share,” intensifying the emotion in your subject lines will likely prove beneficial.

How can you apply all of this to craft improved subject lines? Here are the three steps you can follow:

1. Determine the topic of your email. What is the subject matter? What promises are you making? What issue are you addressing?
2. Apply the “curiosity filter” (the 5 methods) to this idea. Consider each curiosity trigger and brainstorm how you can incorporate them into your subject line to make it more enticing.
3. Enhance the emotion in your new subject line. Swap ordinary words for compelling, emotive ones. (More on this shortly).

A word of caution: Be wary of turning this curiosity filter into clickbait. Instead of employing all 5 methods simultaneously (akin to using a sledgehammer to drive in a nail), select 3 and execute them effectively. How can you incorporate each of the 5 methods? While four of them are relatively straightforward, being unexpected can sometimes pose a challenge. Let’s delve into that next.


Why “weird words” in your email subject lines can help you snag eyeballs

Which is more intriguing?

1. He walked through the door and sat down in the chair.

2. He plodded through the door and sat down in the chair.

The second option, correct? It employs a more powerful verb and provides insight into the character. If desired, you could even enhance it further:

3. He turtled his way through the door and plopped down in the chair.

Unconventional vocabulary is an effective method to capture attention (notice we didn’t say “get attention”). When is it appropriate to employ unusual language?

  • Substitute a less common verb for a typical one.
  • Opt for an unusual adjective or use a stronger verb in place of an adjective.

One of the quickest methods to enhance your language is to replace commonplace “placeholder” words like “easy” or “quick” with more precise alternatives. Which is more likely to seize attention?

1. 5 Quick Ways to Write Good Email Subject Lines

2. 5 Piece-of-Cake Ways to Write Succulent Subject Lines

Seek out unique expressions for ordinary concepts, and you’re more likely to capture attention (as well as garner opens and clicks). (Note: Consider whether your audience will comprehend the term “succulent.” It’s typically advisable to utilize simpler words.)

Brick-and-mortar words make your email subject lines intriguing

Did you know? Not all words are created equal. Some words literally activate different parts of your brain.

Why did we say "snag eyeballs" instead of "get attention"? Why do we use "brick-and-mortar words" instead of "concrete words"? Because, in your email subject lines, it's preferable to employ words that people can visualize. Why? Because, according to research:

  • People can comprehend concrete words more swiftly than abstract words.
  • People recall concrete words more effectively than abstract ones.


Consider this: When you hear "farmer's market," you can immediately conjure an image of one. This visualization occurs instinctively. However, when you hear "justice," what do you envision? Perhaps a jail cell, a judge, or a gavel? Yet, it's not as straightforward to picture, which means it requires more time for processing and understanding (note that the examples provided are still concrete images). Gary Bencivenga, often hailed as the greatest living copywriter, employs this technique in his writing.

sl guide img 1

This excerpt could easily serve as an email subject line. (“Fuzzy dice” epitomizes concrete language. How can you not envision a pair of fuzzy dice? What’s remarkable is that we may not recall the secret itself, but we do remember the phrase “fuzzy dice.” Concrete imagery enhances the intrigue of your subject lines—it’s one of the most effective ways to add an element of surprise. In their bestselling book “Made to Stick,” the authors emphasize the importance of simplicity, unexpectedness, concreteness, credibility, emotional appeal, and storytelling (you’ll notice this spells out “SUCCESS”). The simpler something is to grasp, the more memorable it becomes, and the easier it is to capture attention and elicit clicks.)

11 more email subject line templates you can steal

The email subject line tool above offers numerous subject lines ready for immediate use. But if you want to customize further, there are plenty of other email subject line templates available with just a bit of tweaking. Now that you know how to craft great subject lines, here are some templates to kickstart your creativity:

1. The [famous person] of [category]

For instance: “The LeBron James of carpet cleaning”

Draw a comparison between a renowned individual and a category typically unrelated to them. To execute this effectively:

Ensure the selected person is widely recognized.
Choose a category entirely distinct from the person’s field.
Avoid comparisons like the “Tony Anselmo of washing dishes.” Instead, opt for intriguing combinations such as the “Oprah Winfrey of auto mechanics,” sparking curiosity and interest.

2. [Thing] = [Thing that it shouldn’t equal]?

For example: “Success = Fuzzy Dice?”

Pair two disparate elements that wouldn’t typically be compared. One should relate to your service or product, while the other should be completely unrelated. To master this technique:

Ensure the two elements have no apparent connection.
One of the elements should tie back to your business.
Make sure your email actually presents the comparison, creating an unexpected and captivating premise.

3. The [weird name] technique to get [benefit]

For example: “The ‘Fuzzy Dice’ secret to exploding your sales”

Assign an unconventional name to your solution or technique for addressing a problem, incorporating it into your subject line alongside the benefit. To effectively employ this approach:

Craft a sufficiently peculiar name, ideally comprising an unusual adjective and a concrete noun.
Specify a clear and specific benefit.
Clarify in your email why the technique bears its unusual name, leveraging strange yet evocative titles to pique curiosity.

4. [Challenge / Provocative Question]

For instance: “13 people couldn’t guess the winner. Can you?”

Prompt your contacts to guess a winner or ponder a question about themselves. To effectively utilize this approach:

Ensure the challenge is clear and specific.
Make the challenge seem easy or quick to complete.
Provide the answer to the challenge in your email.
Challenges and provocative questions create an information gap, fostering curiosity when the challenge appears manageable.

5. Why [good thing] is [not good]

For example: “Why your raise might cost you money”

Select something widely perceived as positive and elucidate why it may not be beneficial. To succeed with this tactic:

Choose a good thing that is nearly universally regarded as positive.
Provide a specific reason why it may not be advantageous.
Share the reason within the email content.
Questioning a commonly accepted notion is an effective strategy for capturing attention.

6. Why I turned down [thing everyone wants]

For example: “Why I turned down a free trip to Maui”

Identify something desirable and elucidate why you declined it. To effectively execute this strategy:

Select something universally desired.
Establish a connection between rejecting the desirable thing and your business.
This approach offers a straightforward method to defy expectations.

7. [One word.]

For instance: “blah”

Condense your subject line to a single word. To execute this effectively:

Use it sparingly as it stands out due to its rarity but may lose its impact over time.
Choose a slightly unconventional word.
One-word subject lines are uncommon and can catch the recipient’s attention in their inbox.

8. Well, that [Meeting / Event] went well. (It did not.)

For example: “Well, that dinner party went well. (It did not.)”

Reference a specific event or situation, setting the stage for an unfinished story to pique curiosity. To succeed with this approach:

Select a highly specific event.
Establish a connection between why the event didn’t go well and your business.
Stories are inherently intriguing, particularly when left incomplete. Explain why the event didn’t go as planned and how your product or service could improve similar situations.

9. Don’t [Action]. Trust me.

For example: “Don’t work out at home. Trust me.”

Discourage an action that someone might contemplate, adding intrigue by implying there’s a story behind your advice. To effectively utilize this strategy:

Choose an action that individuals might genuinely consider undertaking.
Provide a backstory or rationale for your advice.
This subject line works by presenting an incomplete narrative and defying expectations by discouraging a typical action.

10. You are [comparative] than you think

For example: “You are richer than you think”

Highlight a positive attribute that individuals desire, then reveal that they already possess it. To excel with this tactic:

Select a positive comparative that resonates with your audience.
Offer an explanation within the email to support the assertion.
This approach cleverly leverages curiosity Method 5 by implying that the recipient possesses knowledge they may not realize.

11. [Say what’s in the email]

For example: “Get 20% off jeans”

Occasionally, straightforwardness outweighs cleverness. While email subject lines typically function as teasers, sometimes directness is beneficial. To implement this effectively:

Ensure that the content of the email aligns with the recipient’s interests.
Avoid overwhelming recipients with excessive repetition or discounts.
Clarity can sometimes be more effective than ambiguity.


[0] Loewenstein, G. (1994). The psychology of
curiosity: A review and reinterpretation. Psychological bulletin, 116(1), 75.

[1] Kang, M. J., Hsu, M., Krajbich, I. M.,
Loewenstein, G., McClure, S. M., Wang, J. T. Y., & Camerer, C. F. (2009).
The wick in the candle of learning: Epistemic curiosity activates reward
circuitry and enhances memory. Psychological Science, 20(8), 963-973.

[2] Berger, J., & Milkman, K. L. (2012).
What makes online content viral?. Journal of marketing research, 49(2), 192-205.

[3] Suri, G., Sheppes, G., & Gross, J. J.
(2013). Predicting affective choice. Journal of Experimental Psychology:
General, 142(3), 627.

[4] Papagno, C., Fogliata, A., Catricalà, E.,
& Miniussi, C. (2009). The lexical processing of abstract and concrete
nouns. Brain research, 1263, 78-86.

[5] Clark, J. M., & Paivio, A. (1991). Dual
coding theory and education. Educational psychology review, 3(3), 149-210.

[6] Heath, C., & Heath, D. (2007). Made to
stick: Why some ideas survive and others die. Random House.

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