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The Best Email Subject Lines: The Ultimate Guide +515 Examples

Karolina Petraškienė
Content Marketing Manager
Reading Time: 13 minutes

Did you know that 35% of customers open your emails based solely on the subject line?

What’s more, 69% of email recipients mark messages as spam based on the subject line.

These two stats confirm the fact that great subject lines are crucial for your email campaign.

A small detail, like the subject line, can determine whether your email will be successful or fail miserably.

But don’t worry—I’ve got you covered.

Today, not only am I going to show you the best practices (keywords, length, and emojis), but also how you can test and optimize it, how to use preheaders for higher conversions, inspiring real-life examples, and other important aspects you need to use to create the absolute best email subject lines.

So let’s discuss how you can increase your open rates and engagement by using an eye-catching email subject line.

If you want to test out your subject lines right now, you can use Omnisend’s Subject Line Tester and get immediate feedback.

screenshot of the Omnsiend subject line tester

Perfect copywriting for the best email subject lines

One of the most important parts of creating great subject lines for your email campaigns is, well, the writing.

You can spend half an hour, or sometimes hours, trying to make your email subject lines perfect. After all, they need to instill curiosity in the reader.

But what if I told you that you didn’t need to spend so much time researching it all by yourself?

In fact, all you need to do is make sure you’re following these 7 important best practices.

That way, you’ll never go wrong with your email subject line copywriting. Below you’ll find a summary of these points, but read on to get in-depth information into how you should be using these and why.

Image summarizing the 10 copywriting tips for high-converting subject lines

#1 Be concise

When it comes to subject lines, there’s no need to start dusting off your academic vocabulary.

What you need to do is be concise: short and straight to the point.

You see, people will only give you a second (or, most likely, a split second) of their attention, so you have to make sure you’re grabbing their attention immediately.

In fact, studies have shown that short and descriptive subject lines, regardless of whether it’s a clearance subject line or subject line for discount offers, fare better than long starters.

That means that you should use about 5-9 words for your subject lines. We’ll dig deeper into the perfect email subject line length below, but the point here is clear:

Don’t waste your readers’ time. Keep it short, simple, and sweet.

Bad: If you wait too long, you won’t be able to get free shipping on our new fall line
: Don’t Hesitate: Get Free Shipping On New Fall Line

#2 Put important info at the front

Leading naturally from my above point, it’s important that you put your important information close to the front of the subject line.

This is because your subscribers will be reading their emails on both desktop and mobile.

And, as you know, you have less space on mobile devices, and if you have a long email subject line, it’ll most likely be cut off.

You don’t want the important information to be cut off, so put that all at the front.

If you have a sale, start your email subject line with “Sale.” If it’s for Black Friday or Christmas, put that at the front.

Bad: These are the 7 beautiful dresses at 50% off in our Autumn Sale.
: Autumn Sale: Get 50% Off These 7 Beautiful Products

#3 Ask a question

One fantastic way to grab your subscribers’ attention is to ask them a question and stir curiosity.

Human psychology is simple: if you ask a question, people will feel curious and will try to answer it. It’s like an itch that they have to scratch.

The beauty of that is that it gives you a few more seconds of their attention, which is always a good thing.

In fact, some of the best subject lines are completely made up of questions. (And some combination of all these subject line best practices.)

Make sure your questions is compelling and related to what you’re selling. One of the worst things you can do is to set expectations in your subject line that your email just doesn’t deliver.

Therefore, don’t ask an irrelevant question as the subject line just so that you can get a higher open rate. That is deceitful marketing and can cause your readers to unsubscribe quickly.

Bad: Don’t you just love our new look?
: Want to save BIG on your next shirt?

#4 Create urgency

Human psychology demands that if you have a long time to do something, you’ll probably wait until the end to do it.

That’s the nature of procrastination, and it’s the reason why you need to create urgency so that people will want to act right now.

With good urgency in your email subject lines, you’ll make sure that your subscribers are opening and clicking now…

…rather than telling themselves they’ll come back to the email (which they probably won’t).

So how can you create that? Simple: put it in your subject line, right at the beginning.

Bad: Make sure you don’t miss all these great deals!
: 24 Hour Sale: Great deals on all dresses–today only!

(That’s what I call the urgency sandwich: begin and end with a time limit.)

#5 Use just one word

Another way to create urgency and curiosity in your readers is by using the least amount of words possible, or even single-word subject lines. An email subject line packed with too many words telling your readers about a limited-time offer can be hard to read.

You can increase your open rates and engagement by using single words that get the information across. Single-word email subject lines are perfect as sale-ending subject lines, clearance and sale subject lines, as well as restock subject lines.

Bad: We have some really great news coming out for all our subscribers!
: This. Is. EPIC.

#6 Use command words

Use strong words when writing your subject lines to get your subscribers’ attention.

For that reason, I recommend strong command verbs. You want to get them to do something, not to know something. Those with a fear of missing out will click on your email instantly.

That’s why words like “take,” “get,” “find,” etc. work well. They’re short and punchy.

Bad: Delicious cakes and sweets for any celebration
: Get these delicious cakes for your next party

#7 Use numbers (when appropriate)

When talking about the best email subject lines, it’s important to reiterate something:

Set and meet expectations.

You want your subscribers to get a pretty good idea of what’s in the email based only on the subject line.

For that reason, it’s important that you try to be as specific as possible.

It’s better to be specific about a sale or discount in your subject line, rather than simply hinting at something.

Bad: Get this amazing discount – ending soon
: Get 25% off all dresses – sale ends today!

#8 Use lists

Craft a great email subject line by using numbers and lists. The fact is that most of the factors that help you curate an excellent blog post also help create a good email subject line.

Lists are easier for our brains to process and inspire curiosity. In addition, they ensure an easy read.

Email marketers use lists because they utilize numbers and punctuation marks: they are eye-catching and jarring. Ultimately, these motivate your readers to open their emails by being visually attractive.

Bad: Some fashion ideas to help you prepare for the fall weather
: 13 stylish fall fashion ideas

#9 Personalize your subject lines

Using your reader’s first name, occupation, or other personal data is an excellent way to curate a personalized subject line. Most email marketing platforms allow users to choose between adding your audience’s first name and last name.

According to research, personalized subject lines help boost revenue, click rates, and transactional rates. However, keep in mind these must be used in scarcity. Why? It is because personalized subject lines are becoming a common practice.

Instead, try to focus on using location-specific subject lines. Let’s take a look at last day sale subject lines:

Bad: Hey (first name), (company name), check out our last-day sale deals!
: 5 Must-Have Hoodies for Stylish Californians

#10 Be consistent

There are two points I’d like to make here:

  • be consistent in your branding
  • be consistent in your writing

The first one is a little harder to define, but it’s pretty important.

If you’ve set a humorous, light tone, you should keep that tone throughout your communications. Don’t just start copying the 515 best email subject lines (below) without first adapting them to your brand.

Consistency is key in brand-building.

The second point is that, well, you need to be consistent in your language and writing.

Choose if you’re using sentence case, like this:

This is the sentence case

…or title case, like this:

This Is the Title Case

But don’t switch it up or, even worse, mix it up in the same email subject line. If you want to be certain you’re using correct, AP-style title cases, there’s this useful online tool to help you.

Whatever you choose, be consistent.

Bad: Come join us For Your Next Birthday Party
Come join us for your next birthday party / Come Join Us for Your Next Birthday Party

Testing, previews and personalization

Now that you’ve got your copywriting skills down to create the best email subject lines ever, let’s go over some other important details.

These are going to cover the other parts of email subject lines not necessarily related to writing.

However, they’re pretty important to making sure your subject lines get you some great open rates.

#1 A/B Test it

Let’s talk about testing. There are two ways you can A/B test your subject lines.

One is based on whether your email marketing platform allows for A/B testing (like Omnisend does), meaning you can send out one subject line to a small group A, another version to a small group B, and the winning subject line goes to the large group C.

That way, you can also test your sender’s name (I discuss why that’s important below) and sender’s email address to see which works best.

The other A/B Testing is what I call: Always Be Testing or ABT.

It’s more manual, but it’s important that you do it throughout your entire ecommerce journey.

One campaign, you can test one style, on another one, test a smaller iteration or a slightly different style, and over time you’ll see what works and what doesn’t.

#2 Always try to be personal

I don’t want to talk about being personal in terms of branding, where you’re presenting your brand personality in a consistent way.

You should definitely do that, but I’ve already covered that above.

Instead, I want to talk about how you can personalize your subject line and sender’s name. And this has to do with testing.

For some people, it’s better to get an email from Alison from The Dress Store, rather than just The Dress Store.

Using the testing I mentioned above, you’ll see in a few weeks which one works best.

But you can also test the more technical personalization, which means including the subscriber’s personal information in the actual subject line.

Usually, this means that you add the name tag in the subject line so that it looks like this:

Lisa, we’ve got some great deals for you!

But, to be honest: this doesn’t work for everyone. I don’t like it when I see it, and many others won’t either.

But you shouldn’t just limit yourself to the name tag. Why not add email personalization in a different way.

Segment users based on their location, and if you see that Miami is going to have a rainy week, send them this kind of email:

Wet week in Miami – get 20% off our colorful umbrellas

Here, ABT still applies. Test, and see what works for your store.

#3 Always use preheaders

Preheaders can be seen as the preview text of the email.

It immediately follows the subject line, so that people can have an even better idea of what the email is all about.

By default, it’s the first few words of the email text (about 30-50 characters).

Make full use of preheaders for your email subject lines

But if you’re not customizing your preheader, you’re losing the opportunity for even better open rates.

Therefore, instead of just having this as your subject line:

Get 25% off all dresses – sale ends today!

…you can instead customize the preheader so that it looks like:

Get 25% off all dresses – sale ends today! – 24 hour discount off Summer, Maxi, Midi, Stripe dresses

It’s a good opportunity for you to re-emphasize the subject line, as well as add more important (and compelling) details.

Common email subject line questions

Before we look at the best email subject lines (that should inspire you) based on Omnisend research, let’s go over some burning questions you may have.

As with anything in eCommerce, there’s a lot of mystery that surrounds certain topics, and email subject lines are no different.

So let’s look at some of the most common questions you probably have.

#1 What’s the perfect subject line length?

There is no perfect subject line length for all emails and brands, but based on Omnisend research, email subject lines perform best if they are 21-30 characters long.

For you: ABT. For a week or two (depending on your emailing frequency), see which subject line lengths perform the best for your store.

#2 Should I use emojis in my subject lines?

Emojis can be great for your brand, or they can seem out of place.

The best question I would ask you is: do emojis fit into your brand personality?

If they do, then you should definitely use them. If not, you can still test it by adding one emoji in your subject line and see how it works.

After all, one of the best reasons for using emojis is that they save space, so you can do something like this:

Get FREE shipping on all ????!

For example, Zalando Lounge uses emojis in every subject line. Mainly, for getting more attention. See below how it looks.


#3 Will the word ‘free’ send my emails to spam?


This is one persistent myth that confuses the word ‘free’ with the frequency and abuse of shady companies that use the word ‘free’ in their email marketing.

Meaning: companies that send a lot of spammy emails will end up in the spam inbox. It just so happens those types of businesses love to use the word ‘free’ as well.

But that doesn’t mean that all businesses that use that word end up in spam. It’s more about how you send emails, and how many of your subscribers unsubscribe from you, or report you as spam.

So, using ‘free’ is fine.

You can test your own subject lines with Omnisend’s email subject line tester to help you perfect your subject line.

#4 Can I use all caps or exclamation marks?

You can, sparingly.

Meaning: putting one to three words in all caps is fine, such as ‘SALE’ or ‘ONE DAY’ or even ‘24 HOUR SALE’.

But don’t put the entire subject line in all caps, seeing as on the internet, that means you’re yelling at them.

And no one likes to be yelled at.

For exclamation marks, the same goes: use sparingly.

Don’t add 3 exclamation marks when one will do (the same with question marks). It comes off as angry.

Don’t use exclamation marks and questions marks in the same subject line, and never use them back-to-back.

Try using a special approach for subject lines when you’re giving the reader a new update, so that it catches their eye. One example is for a restock email subject line. Telling customers that their favorite products are back in stock is a big deal, so treat it as such.

Bad: Are you excited for the BEST deals ever?!?!
Are you excited for the BEST deals ever?

515 high-converting subject lines

Sometimes it’s hard to come up with amazing subject lines all on your own.

Sometimes you just need some inspiration.

That’s why I’m going to give you the best of the best email subject lines—on every topic starting from free shipping subject lines right down to discount email subject lines.

You see, we’ve already done the research for you.

But let me warn you: some of these successful subject lines don’t follow any of the best practices I’ve listed above. And yet, they were successful.

So let’s look at some of the best subject lines based on these popular topics.

Below, I’ll also give you the link to download our FULL report on the 515 best, data-backed subject lines for high open and click rates (and, of course, sales).

#1 Black Friday subject lines

#1 Subject line: Black Friday Weekend Banger

  • Open rate: 44.85%

#2 Subject line: BLACK FRIDAY SALE / Kendrick Lamar x Reebok Classic CL Luxe Olive / Bedwin x The Heartbreakers x Adidas Originals collection

  • Open rate: 42.79%


  • Open rate: 33.51%

#4 Subject line: Save 40% @ [store] Black Friday Sale

  • Open rate: 30.36%

#5 Subject line: Two Day Sale This Weekend

  • Open rate: 29.58%

If you want more subject lines, read our post on The Highest Converting Subject Lines For Black Friday Campaigns.

#2 Summer email subject lines

#1 Summer email subject line: “Summer Sleepwear Sale”

  • Open rate: 51.6%

#2 Summer email subject line: “SUMMER DISCOUNT!”

  • Open rate: 38.5%

#3 Summer email subject line: “Soleus Running Summer 2017”

  • Open rate: 38.3%

#4 Summer email subject line: “Summer Gets Better!”

  • Open rate: 37.1%

#5 Summer email subject line: “the summer has finally arrived”

  • Open rate: 35.6%

If you want more subject lines, read our post on the 81 Summer Email Subject Lines for Your Next Summer Campaign.

#3 Memorial Day subject lines

#1 Memorial Day subject line: “30% Off Memorial Day Sale

  • Open rate: 44%

#2 Memorial Day subject line: “Memorial Day savings – save 25% off EVERYTHING!!

  • Open rate: 38%

#3 Memorial Day subject line: “HAPPY MEMORIAL DAY WEEKEND!

  • Open rate: 37%

#4 Memorial Day subject line: “Memorial Day Secrets

  • Open rate: 34%

#5 Memorial Day subject line: “MEMORIAL DAY WEEKEND PROMO: Memorialday17

  • Open rate: 33%

If you want more subject lines, read our post on the 90+ Best Memorial Day Subject Lines Ideas.

#4 4th of July subject lines

#1 4th of July email subject line: “Independence Day Special

  • Open rate: 30.3%

#2 4th of July email subject line: “Independence Day Weekend Special: Free Shipping Over $75, Coupon, and New Africa Twin Items!

  • Open rate: 27.3%

#3 4th of July email subject line: “LAST DAY Independence Day Sale | up to 70% Off

  • Open rate: 23%

#4 4th of July email subject line: “Independence Day Bead Deals, up to 70% Off!

  • Open rate: 22.9%

#5 4th of July email subject line: “INDEPENDENCE DAY SALE!

  • Open rate: 21.4%

If you want more subject lines, read our post on the 4th of July Email Subject Lines: 40+ Ideas to Inspire Your Next Campaign.

#5 Mother’s Day subject lines

#1 Mother’s Day subject line: “Mother’s Day Sale

  • Open rate: 37%

#2 Mother’s Day subject line: “25% Off Plus FREE Lip Gloss Mother’s Day Special 🙂 ”

  • Open rate: 32%

#3 Mother’s Day subject line: “A Gift for Mom & A Gift for You!

  • Open rate: 31%

#4 Mother’s Day subject line: “Happy Mother’s Day Weekend!

  • Open rate: 26%

#5 Mother’s Day subject line: “Celebrate Mother’s Day with us!

  • Open rate: 22%

If you want more subject lines, read our post on the 170+ Best Mother’s Day Subject Lines Ideas.

#6 Father’s Day subject lines

#1 Father’s Day subject line: “Father’s Day Gift Ideas

  • Open rate: 32.6%

#2 Father’s Day subject line: “Get Father’s Day sorted!

  • Open rate: 32%

#3 Father’s Day subject line: “This Father’s Day, he deserves something special!

  • Open rate: 31.3%

#4 Father’s Day subject line: “Fathers Day Sale, Tons of Movies Restocked

  • Open rate: 30.3%

#5 Father’s Day subject line: “Gemini Jets For Fathers Day!”

  • Open rate: 27.9%

If you want more subject lines, read our post on the 125+ Father’s Day Subject Lines for Amazing Results.

#7 Back to school subject lines

#1 Back-to-school subject line: “BACK TO SCHOOL! Come join the FUN! ?”

  • Open rate: 28.6%

#2 Back-to-school subject line: “OH DEER POP UP SUPER SALE! Back to school Shopping!”

  • Open rate: 22.5%

#3 Back-to-school subject line: “$5 Back to School Deal  ✏️”

  • Open rate: 21.6%

#4 Back-to-school subject line: “Back to School never looked so good! Specials all week!”

  • Open rate: 20.3%

#5 Back-to-school subject line: “30% OFF BACK TO SCHOOL SALE  ?”

  • Open rate: 18.3%

For more subject lines, read our full post: 67 Back to School Email Subject Lines (That You Can Steal)

#8 Fall email subject lines

#1 Fall email subject line: “[Brand Name] colour for Fall”

  • Open rate: 53.1%

#2 Fall email subject line: “[Brand Name]’s back for fall”

  • Open rate: 50.2%

#3 Fall email subject line: “FALL FREEBIE”

  • Open rate: 41.5%

#4 Fall email subject line: “?The [Brand Name] Start of Fall Sale!?”

  • Open rate: 39.2%

#5 Fall email subject line: “New Post – How To Wear Long Coat This Fall”

  • Open rate: 36%

For more subject lines about fall (autumn), read our full post: The 63 Best Fall Email Subject Lines (Backed by Research).

Get loads more amazing email subject lines

Still looking for more?

Then you’ll want to get our free ebook: 515 High-Converting Subject Lines.

It has everything you need to make sure you’ll have the best email subject lines for the entire year.

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Karolina Petraškienė

Karolina is a writer, content marketer, and email enthusiast at Omnisend. When she's not curating articles, you can find her in the woods challenging herself in hiking boots or off-roading her bike.