Inbox standouts: 9 great email subject line examples and why they work

Profile photo of author Tiff Regaudie
Tiff Regaudie
11min read
Email marketing
December 13, 2023
On the left side of the image, the text "subject lines" is stacked three times in all caps, in a shade of dark salmon on a background of light lavender. The gradient of the image fades into a bright salmon on the left side of the image, where text in white font reads, "9 great email subject line examples and why they work"

The subject line is the most important piece of copy you’ll write for your email marketing strategy.

We don’t make this statement lightly. Body copy and CTAs are the meat and potatoes of your marketing emails, and you wouldn’t see clicks and conversions without them.

But you wouldn’t see any results without effective subject line copy—because it’s what gets someone to open your email in the first place.

In fact, we think subject lines are so important that we conducted research to define a few basic email subject line best practices, which found:

  • Personalized emails earn higher open rates.
  • Most great subject lines create a curiosity gap.
  • Short subject lines that look complete on mobile perform better.
  • Urgency and scarcity prompt people to open emails.
  • Context rules all good email content performance—including subject lines.
  • Emojis aren’t bad in subject lines, but use them sparingly.
  • Thoughtful preview text can make a good subject line great.

But if you’re here more for inspiration, we’ve picked through a lot of our customers’ subject lines so we could highlight the ones that embody those first principles. Here are a few of our favorites—with details on what makes them stand out:

1. Supply uses an emoji to convey context

Subject line: This email is better than 👇

Most email marketers understand context, in theory—they know their emails are showing up in the flooded inboxes of overwhelmed, busy people.

But the marketers at shaving brand Supply go one step further than comprehension. With this cheeky subject line for BFCM, they make damn good use of an emoji to show they understand the context of the average inbox. With solid reinforcement from their preview text, Supply crafts one of the most creative yet simple subject lines we’ve ever seen.

Image shows a screenbox of an inbox promotions tab, with an email from shaving brand Supply at the top followed by emails from Beardbrand, ChatBot, and Wisepops. Supply’s subject line reads, “This email is better than” with an arrow pointing down emoji. The preview text reads, “Prove us wrong. Don’t open it.”
Image source: Twitter

2. Dagne Dover prioritizes mobile with a punchy subject line

Subject line: To you, from you

“Most email opens are happening on mobile devices, so it’s critical to think mobile-first when you’re writing subject lines,” says Dayna Scandone, principal customer success manager at Klaviyo.

“You should always be testing your email campaigns on desktop and mobile to ensure they’re showing up exactly how you want them to, and that includes the subject line,” Scandone adds.

You should always be testing your email campaigns on desktop and mobile to ensure they’re showing up exactly how you want them to, and that includes the subject line.
Dayna Scandone
Principal customer success manager, Klaviyo

You don’t necessarily need a super short subject line to see high email open rates—the average word count is 7, according to our research. But at the very least, your subject line should look great on mobile.

Dagne Dover, the brand that creates “problem-solving bags for problem-solving humans,” demonstrates a mobile priority with this subject line that’s just 4 words long. It stands out in an inbox not only because it’s shorter than other subject lines, but also because it’s so concise and direct.

Image shows a screenbox of the top of an email from bag brand Dagne Dover. The subject line reads, “To you, from you.”
Image source: Dagne Dover

3. Beekman 1802 builds urgency for a free offer

Subject line: LAST CALL 📣 Free Mini Milk Drops

All caps, an emoji, and a freebie available for a limited time—these are the ingredients of a subject line that inspires a sense of urgency.

Image shows a screenbox of the top of an email from skincare brand Beekman 1802. The subject line reads, “LAST CALL,” with a megaphone emoji: “Free Mini Milk Drops.”
Image source: Beekman 1802

Assuming skincare brand Beekman 1802 sent out a couple emails before this one to communicate the offer, this is a great subject line for everyone on the email list who didn’t buy during previous rounds. If you’re sending last chance reminders like this, you’ll want to exclude people in the segment who already took action from previous emails in the series.

Image shows the body of an email from skincare brand Beekman 1802. The brand’s logo and tagline, “There is beauty in kindness,” appear with a free shipping notice above the headline, which reads, “Free Milk Drops Ends Tomorrow.” The background of the email is a product shot of the advertised milk drops against a backdrop of snow, and the body copy encourages readers to “Treat your winter skin to the hydrating power of our Clinically Kind Skincare and get a free mini Milk Drops with every skincare purchase.” Finally, the CTA button reads, “Shop now.”
Image source: Beekman 1802

Word of caution: Be careful that the urgency and FOMO (fear of missing out) you communicate don’t use email spam trigger words—words and phrases that, when included in your company’s emails, can land them in your recipient’s spam folder and negatively affect your email deliverability.

Image reads EMAIL DELIVERABILITY (in all caps) and, over to the left, Avoid the spam folder for maximum engagement.
Your complete guide to email deliverability: avoid the spam folder for maximum engagement
A deep dive into email deliverability: what it is, what affects it, best practices and brand examples.

4. Dossier creates a curiosity gap for customers

Subject line: ✨Something NEW is coming…✨

If you’re sending an email to customers—especially VIPs—what better way to hook them than with something new?

Image shows a screenshot of an email subject line from fragrance brand Dossier, which reads, “Something NEW is coming…” with sparkle emojis on either end.
Image source: Dossier

Fragrance brand Dossier evokes curiosity with this simple, clear subject line. It may not work on people who don’t have high purchase intent, but on the flip side, it can work really well on people who have bought before. (Ahem—this is why email segmentation is so important.)

Image shows the body of an email from fragrance brand Dossier, featuring a model holding an illustrated bottle of perfume. In white font on a salmon background, the headline reads, “Introducing Dossier originals.” The email goes on to address the recipient as “Dearest reader,” explain the new product line, and ask, “Are you ready to join us in the future of fine fragrance?” Finally, the CTA button at the bottom reads, “SIGN UP TO GET NOTIFIED.”
Image source: Dossier

5. Reverie’s subject line and preview text go hand in hand

Subject line: Are you washing your hair properly?

Preview text: How to do it right

As Toccara Karizma, CEO of Karizma Marketing, points out, “Solving a pain point in your subject line can work well to encourage email opens.”

Solving a pain point in your subject line can work well to encourage email opens.
Toccara Karizma
CEO, Karizma Marketing

Haircare brand Reverie hints at solving a pain point by asking a provocative question in their subject line and expanding on it with their preview text. It’s a great example of how to keep your subject line short while using the extra real estate of your preview text to widen the curiosity gap.

Image shows the body of an email from haircare brand Reverie. Above a shot of a model shampooing their hair, the headline reads, “Wash, wash, baby.” Below the image is a provocative statement: “There’s a right way and a wrong way to wash your hair,” followed by a CTA that says simply, “Read more.”
Image source: Reverie

6. House Of Harlow 1960 plays into the popularity contest

Subject line: Our most popular necklace is back in stock!

If something goes out of stock quickly, it must be good, right? A subject line that says, “Our most popular necklace is back in stock!” makes customers want to check it out immediately. House Of Harlow 1960 is a well-known jewelry brand that uses this tactic to inform customers when a bestseller is available again.

Image shows a screenshot of an inbox, side by side with a screenshot of an email from jewelry brand House of Harlow 1960. In the inbox, we see a subject line that reads, “Our most popular necklace is back in stock!” The body of the email contains a photo of a model wearing the necklace in question, advertised as “Raw emerald necklace” in the email’s headline, which appears beneath the brand’s logo.
Image source: Milled

7. Fly by Jing demonstrates empathy for tough holidays

Subject line: Want to opt out of Father’s Day?

Sauce and seasoning brand Fly By Jing thinks ahead of Father’s Day by thinking about people who may not want to celebrate it. With a subject line that hits home for many, the brand pulls people in with the most important marketing attribute: empathy.

Image shows the body of an email from sauce and seasoning brand Fly By Jing. Featuring the brand’s characteristic bold color scheme with bright yellow font on a kelly green background, the email gives readers the option to opt out of Father’s Day marketing emails with a bright orange CTA button that reads, “Mute Father’s Day.”
Image source: ReallyGoodEmails

8. OSEA gets personal with a unique discount nudge

Subject line: Your 10% Off Ends Soon!

Vegan skincare brand OSEA Malibu draws people in with the most powerful subject line tactic there is: personalization.

Image shows a screenshot of an email subject line from skincare brand OSEA Malibu, which reads, “Your 10% Off Ends Soon!”
Image source: OSEA Malibu

When we hear “personalized email subject lines,” we often think first or last names. But this simple subject line takes personalization beyond the surface level by using the email recipient’s unique profile data—in this case, an expiring coupon code—to encourage an imminent purchase.

Image shows the email body of a message from skincare brand OSEA Malibu. In dark green font on a light sage background, the email headline reads, “Last call: save 10%” and includes the recipient’s unique discount code above a CTA button that reads, “Shop now.”
Image source: OSEA Malibu

9. Wildfang sends a friendly—and witty—reminder

Subject line: Did I just get ghosted?

Genderless apparel brand Wildfang pairs witty copy with personalization in the subject line of this browse abandonment email automation.

Image shows a screenshot of an email subject line from apparel brand Wildfang, which reads, “Did I just get ghosted?”
Image source: Wildfang

By combining a reference to the recipient’s unique web browsing history with a cute spin on a phrase from the world of dating apps, the brand crafts a question that’s hard for their millennial audience to resist answering in the form of an open.

Image shows the body of a browse abandonment email from apparel brand Wildfang. Beneath the brand’s logo and store categories, the headline reads, “Want u back” over an image of the product the recipient recently abandoned. The CTA button at the bottom reads, “Get yours.”
Image source: Wildfang

What’s next: using AI as your subject line assistant

Inspiration before writing is always great, but you can take it a step further by using AI to generate inspiration on the spot. Learn more about how Klaviyo’s subject line AI can help you generate better emails that convert—at scale.

Power smarter digital relationships.
Try Klaviyo
Tiff Regaudie
Tiff Regaudie
Tiff (she/they) is a writer and content consultant who specializes in marketing, health, and the attention economy. Before devoting herself to freelance writing full-time, they led content teams at various startups and nonprofits in Toronto, Canada.