50+ Best Cold Email Subject Lines To Improve Your Open Rates

If you’re pouring all your creativity into perfecting your email content and leaving your cold email subject line as an afterthought, you’ve found the culprit for your underperforming campaigns. 

33% of recipients open their emails based on the subject line, according to a study by SuperOffice. So, optimizing it is one of the best ways to improve open rates and, ultimately, response rates and conversions. 

After all, how can you expect to get a reply and nurture a lead if they don’t open the email?

Here, we discuss what goes into nailing a cold email subject line and 10+ types of cold email subject lines with examples to help you drive open rates. 

Source

What Makes a Good Cold Email Subject Line? 

According to Chase Dimond, a sales email expert,

‘An okay email with a great subject line will outperform a great email with an okay subject line, every time.’ 

Subject lines in cold emails are like windows into your email. If they’re not attractive enough, nobody will step in no matter how well you’ve crafted your cold email

 ‘The subject line doesn’t sell the product, it sells the open,’ says Chase.

Approaching your subject lines in cold emails with this in mind keeps you on track and helps narrow down the best cold email subject line. Here are three ingredients to whip up the perfect email subject lines:

1. Keep It Relevant

You need to get into your prospect’s shoes and understand their motivations and goals. Then, use this information to make the subject lines of your cold email interesting. 

This means offering value to your prospect and answering the age-old question-what’s in it for them. Why should they open your email? Give them a reason and be specific. 

Next, personalize your cold email subject lines.  Take their name, mention their company, or even their latest post on LinkedIn. This will help your cold email stand out in their inbox, making them feel less like a name on a list and be more inclined to engage in a conversation. 

Lastly, don’t forget to create urgency in your cold outreach email subject line. The best way to do this is to emphasize scarcity. This will encourage the prospect to open the email promptly. 

But a word of caution—be careful not to come off as pushy or too sales-y. This might put off the recipient and give your email a direct flight to the spam folder.

2. Keep It Short

Short and crisp might as well be the subject line mantra. Why? Because the most optimum subject line length is just 7 words. So, you need to make your case quickly. 

Joel Thomas, a top-performing SDR at Almabase, also subscribes to the same idea. He restricts his email subject line to a maximum of 4 words. 

He believes in using those 4 words to spark enough curiosity in the reader to make them open it. A great example is- ‘Got a minute, {prospect name}?’

3. Keep It Free of Clickbait

The third and final ingredient for a good cold email subject line is to avoid sounding like clickbait. Yes, your cold sales email subject line’s aim is to drive open rates, but that’s just one step in the customer journey. Your ultimate goal is to build a strong relationship with your prospect to retain them in the long run.      

These might shock the reader into opening the email. But as is the case with clickbait subject lines, if they over-promise and the email content doesn’t deliver, you’re looking at them hitting the ‘unsubscribe’ link or, worse yet, sending it straight to spam. 

And that’s the case if the spam filters don’t catch on early on. Clickbait words like ‘clearance’, ‘free’, ‘discount’, etc., are like bright spots to spam filters. Including these words in your subject lines might trigger spam filters and lead to low email deliverability. 

This might seem like a long checklist but fear not, we’ve got you covered. Let’s look at the best subject lines for cold emails that you can take inspiration from.

11 Cold Email Subject Lines With Examples

Let’s put theory to practice and hash out some effective cold outreach email subject lines that you can put to use right away.

1. Personalized Subject Lines for Cold Emails

Why Should You Personalize Our Subject Lines?

Personalized cold email subject lines work great for the simple reason that in the sea of their inboxes, prospects find something familiar. So, go beyond their first name and address their pain points, interests, or a mutual connection. This adds that extra touch that makes them feel special. 

Kyle Coleman SVP of Marketing at Clari, says ‘If you don't take the time to understand a person or company before reaching out, why should they take the time to pay attention to you? You don't have to be a complete student of their business, but you need to know enough to show them you understand their challenges and can offer some help.’ 

Further, personalized subject lines get a higher open rate than non-personalized ones. A view that Kyle endorses.

‘‘Keep them short, and personalize the first line of your email to maximize opens & replies.’

Personalized Cold Email Subject Line Examples

1. Here’s how you can solve {pain point} 

Short, crisp, and personalized, this email subject line allows you to pique your prospect’s interest while not coming off as sales-y. Do your research and find out what’s plaguing your prospect and then use that to make a personalized cold email subject line. 

2. {Prospect’s favorite sports team} just made it to quarters! 

This is a great way to break the ice with your prospect. Check out their social media accounts to find out their interests, and in this case their favorite sports team, and use it to build common ground with them. They’re sure to open an email that appeals to their interests.

3. Exclusive offer for {prospect's industry} leaders like {prospect's name} 

Who doesn’t love a bit of flattery? This subject line is sure to win them over and encourage them to see what the offer is about. 

4. From one {Prospect's Alma Mater} alum to another: Let's discuss {Shared Interest/Challenge}

The idea is to find common ground between you and the prospect. This subject line will bring forth nostalgia and familiarity to get your email opened. 

5. Hi {prospect name}, {prospect’s pet}’s going to love this

Never underestimate what this can do for a true pet lover. If your prospect has a dog, car or even a tarantula they can’t stop talking about online, use that and craft a cold email subject line that will drive open rates.

2. Cold Email Subject Lines Asking Questions

Why Should You Use Questions in the Subject Lines?

Questions need answers-that’s how humans are wired. Why not take advantage of it in your cold email subject lines? Including questions in your lines will pique your prospect’s interest enough to encourage them to click on your email.

Sam Holeman, an SDR at Momence, says, 

‘This is like a basic lesson from college: You can start an essay by asking a question that makes you go up, that makes everybody pay attention.’

Posing questions in your outreach email subject lines will entice prospects to open the email to get an answer. 

Examples of Subject Lines With Questions:

1. {prospect name}, want to level up?

The answer is a resounding YES. And reading this sales email subject line, your prospect is going to want to know how. 

2. Looking to boost {specific task} ROI?

ROI is like a golden phrase. It’s going to get your prospect’s attention. And being specific about a certain function—for example, contact marketing ROI or email marketing ROI—you can further pique their interest to open the email.

3. Curious {prospect name}? Let's connect.

Even if they weren’t intrigued before, they are now. This gets your prospect’s eyebrows up and gets them reaching to open your cold email.  

4. How are you solving {pain point}?

Your prospect’s pain point will never leave their mind. And if you refer to it directly while also insinuating there are various ways to solve it, they’ll be running to open it in no time.

5. How does {competitor} do it?

Knowing what your competitor is up to is a cardinal rule of running a successful business. Using this as a subject line in your cold email will immediately capture your prospect's attention, prompting them to open the email to learn more.

3. Highlighting Mutual Connections

Why Should You Mention Mutual Connections?

If you have a mutual contact with the prospect, don’t let it go to waste. Leverage the common ground to start a conversation. And don’t wait for them to open the email to learn this. Add it to your sales email subject line instead. 

Doing this essentially makes you less of a stranger and adds credibility and trust to your interaction. Not to mention, it lets your prospect know you’ve done your research and not approached them blindly. 

Cold Email Subject Lines With Mutual Connection

1. {mutual connection} recommended I contact you

You can simply state this in your cold sales email subject line. This reduces the ‘coldness’ of your email and lets them know they are exactly who you’re looking for. 

2. Hi {prospect name} we met at {event}

Mutual connections don’t always have to be a person. It can be something that gives you common ground. Add that in your cold email subject lines to stand out in your prospect’s inbox.

3. Really enjoyed your post on {common social group}

Flatter your prospect. Who doesn’t like a compliment? Do your research, and if they shared something that caught your attention, let them know in the email subject line itself.

4. Referral from {mutual connection}

You can also keep it simple and straightforward, like this email subject line. State your mutual connection, and it will make your prospect curious to learn why you’re reaching out.

5. {mutual connection} wants us to meet?

This will warrant a response, and the prospect will open it for that alone. So, if you have mutual connections with your prospects, go ahead and name them. This puts you on a higher rung than other cold emails, having come through a familiar name.

4. Short Cold Email Subject Lines

Why Are Short Cold Email Subject Lines Better?

41.6% of email users check their emails on their mobiles. That means the subject lines in your cold emails are at a risk of getting truncated if they’re too long. In other words- not the best first impression, and no emails opened. 

Nikita Solberg, Deel’s top-performing SDR, says they keep their subject lines usually between 3 to 5 words, ‘A lot of people are checking their emails on their phone nowadays. They can really only read a couple of words on their phone.’

G2’s Nanditha Menon also propagates short cold email subject lines, keeping them between 4 to 5 words for better mobile readability. Kyle Coleman says going beyond 9 to 10 words is death. 

The verdict? Sticking to short email subject lines is best. In fact, one-word subject lines garner an open rate of 34.47%, according to an in-house study at Klenty.

However, proceed with caution on this one. Your prospect is, after all, a person, not a robot. So, make sure you’re convinced they’ll appreciate a one-word subject line and won’t find it off-putting.

Short Subject Lines for Cold Emails

1. Solve {pain point}

Short and to the point. This subject line does the job in just two words while addressing a pain point and personalizing the email. Your prospect is naturally more likely to click something that respects their time. 

2. Ideas for {prospect’s company’s name}

Crisp, relevant, and to-the-point. This subject line implies you have insights or solutions that can add value to the prospects company, increasing their chances of opening and engaging with your email. 

3. Quick question

Two words. That’s enough to work your prospect’s appetite to learn what’s the question. This cold email subject line is an excellent example of keeping it short. 

4. Exciting opportunity {prospect name}

What’s exciting? Am I missing out? You best believe your prospect is wondering this when they read this subject line. And to get answers, they’ll need to open your email.  

5. Let’s discuss {prospect’s pain point}

This short email subject line will stand out in your prospect’s inbox. Why? For two reasons. Firstly, it’ll fit their mobile email inbox perfectly and secondly, it invites them to talk about a specific challenge they’re facing.

5. Cold Email Subject Lines That Create Urgency

Why Are Subject Lines That Create Urgency Effective?

If your prospect holds back after seeing your email, chances of it ever getting opened are slim. The trick is to emphasize urgency in the cold email subject line itself. And you do this by leveraging FOMO. 

The fear of missing out can be a powerful catalyst to driving your open rates. Convince your prospect that they’re going to regret not opening your cold email with the subject line itself. You could refer to an event, a new government policy, the end of the fiscal year, or even a discounted offer. 

If your prospects fear losing something others might gain from, they’re not going to waste a second dilly-dallying. In fact, subject lines emphasizing urgency can increase open rate by 22%.

Making your prospect feel like they’re on a time-sensitive task can help you drive open rates. 

Fomo-Inducing Cold Emailing Subject Lines

1. Just one week to go for {event name}

Encourage your prospect to open your emails by giving a countdown. This gets them wondering what the event is about, compelling them to open the mail. 

2. Don’t miss out on {offer}

This leverages FOMO to push the prospect to learn about the offer before it lapses. This subject line works well if you extend limited-time offers to new customers. 

3. [URGENT] You’ve got 1 day before {regulation law} kicks in

Does anything do it better than ‘urgent’ right in the cold email subject line? We think not. Especially if you’re referring to something as dire as a new law or government policy. Ignorance of law is not a defense, and so knowing how it’s going to change their operations, is priority. 

4. {prospect name}, last chance to claim your spot!

There’s no better way to induce FOMO than by informing your prospect that they’re running out of time to gain access to an exclusive event. This subject line encourages your prospect to open the email before it’s too late. 

5. Hi {prospect name}, {value add} is finally here!

This subject line encourages your prospect to open the email to satisfy their curiosity. What’s finally here? And how does it benefit them?

6. Value-Driven Cold Email Subject Lines

Why Should You Use Value-Driven Subject Lines?

Your cold email subject line is crucial when it comes to open rates. Prospects will take just one look at it and decide whether your email deserves an open. Why? Because they fear the email won’t offer any value and waste their time. 

With a value-driven cold outreach subject line, you can effectively tackle this fear. Answer the ‘what’s in it for me’ from the get go.  By including relevant and valuable information right in your email subject line, you can encourage higher open rates. 

Noel K, SDR manager here at Klenty says, ‘‘Book More Meetings’ and ‘Increase Your Revenue’ are some of the go-to subject lines that never fail to get opened. Even though these look like clickbait at first glance, they’re very related to our value proposition.’

Value-Driven Email Subject Lines for Sales

1. Save {savings in percentage} with {value add}

Anything that can help your prospect save money or drive profits is bound to catch their attention. And by adding the value proposition in the subject line, you can pique their interest to open and explore your email further. 

2. X best ways to drive sales

This email subject line works because of how specific it is. It gives the prospect X number of ways to achieve their goal. Giving them a definitive way of achieving something they want nudges them to open your cold email.

3. {company name} + {product name} = {benefit}

In addition to mentioning your product, you’re also informing the prospect of what it can do for them. When you state what your product brings to the table right from the email subject line, you’re demonstrating credibility in bringing value to them. 

4. Double your investment in X days

This lets your prospect know exactly what you can do for them. Not only are you presenting a lucrative opportunity for significant financial gain, you're also specifying the expected timeframe, making them curious to explore the email further. 

5. Drive your {specific task/process} ROI with us, {prospect name}

This cold email subject line tells the prospect exactly what they’re going to gain from your email, which in this case is improved ROI on a specific process. And hitting the mark on their pain point will further help you boost open rates.

7. Funny Sales Email Subject Lines 

Why Do Funny Cold Email Subject Lines Work?

Adding a pinch of humor to your subject line in cold emails can be a good idea. Why? Because your prospect’s inbox is flooding with drab emails, all claiming to be the best. Adding a little fun to their inbox will certainly catch their attention. You can do this by adding humorous cold email subject lines or even including fun emojis.

Sam Holeman uses emojis to draw connections between his company’s marketing initiative and his outreach. So, if the marketing department has mailed a bottle of wine and a pineapple to each prospect as part of a physical warming up campaign, he’ll add a couple of wine and fruit emojis in his cold email to those prospects to give them instant recall. 

‘It’s a tee up for the salesman, and it works great. Actually, people really appreciate it,’ he says.

But a word to the wise—be careful with humor. What you find funny may not tickle your prospect. So, make sure you know what they find humorous. Check out their social media activity to learn this.

Funny Subject Lines for Cold Emails

1. Hi {prospect name}, Doughnot miss this!

Bad puns and a play on words can make for interesting cold email subject lines. You can also use variations like- ‘here’s how we’re raisin’ the bar’ or ‘Here’s a flan-tastic business idea’.

2. Is it Oppenheimer or Barbie?

Pop culture references and trendy topics are excellent additions in subject lines. These offer the recipient a break from the daily grind while also piquing their interest. Check out what’s making headlines and add a reference to your subject lines and see open rates soar.

3. Before you Google this

Google has slowly become our most trusted resource. And by insinuating that the prospect would want to Google something to confirm it, this funny subject line for cold emails prods the prospect to open the email and check out what it contains. 

4. IT’S HEREEE! (Sorry for yelling)

This sales email subject line conveys your excitement while being light-hearted about it. And among the jargon-y emails your prospect gets daily, this subject line triggers instant curiosity.  

5. When did you last check your pockets?

The absurdity of this subject line is what gets your prospect’s attention. Why would they need to check their pockets? They’ll be clicking your email to answer this. 

8. Cold Email Subject Lines With Social Proof

Why Do We Need To Add Social Proof in Subject Lines?

How many times have you sought recommendations from your family and friends? Probably enough times to know they can be helpful in making a purchase decision. Well, we apply the same principle to cold email open rates. Social proof carries substantial convincing power in decision making. And including it in your cold email subject lines can help you nudge the prospect into opening the email. 

You can include social proof in the form of customer testimonials, product reviews, case studies, or even endorsements. 

Cold Email Subject Line Samples With Social Proof

1. {customer name} just fixed {pain point}

If you’ve helped a customer address a common pain point, it can make for a great email subject line. The prospect will be naturally interested in learning how it happened and open your cold email. 

2. Top-rated products that boost productivity

This cold email subject line lets the prospect know that you’re not just pitching a product but backing it with client ratings. And that encourages them to open your cold email.

3. 78% of consumers say yes

Curiosity-inducing, statistics, and social proof, this subject line includes all three to make for a good subject line that can drive your open rates.

4. Mark Cuban swears by this!

Mark Cuban is a well-known businessman, and if he finds something valuable, it’s going to pique your prospect’s interest. However, be careful to add personalities that resonate with your target audience. While this might be a great B2B cold email subject line, it might not work for a teenage apparel audience.

5. I love {product name}- {influencer}

Influencers can be a great resource to use in your subject lines. Sharing their views on your products is a powerful way of increasing your open rate. 

9. Curiosity-Provoking Sales Email Subject Lines

Why Do Curiosity-Evoking Sales Subject Lines Work?

Curiosity killed the cat but not the prospect. Building a little suspense and appealing to the Sherlock Holmes in your prospects can help your cold emailing subject lines drive open rates. But be sure not to sensationalize so as to annoy your prospect. A fine balance must be maintained. 

Chase Dimond says,

‘Curiosity is one of the greatest emotional drivers humans have. So do your best to create as much of it as you can in your subject lines. How?

- Bold claims

- Clear benefits

- Emotional statements’

Curiosity-Evoking Cold Email Subject Line Examples

1. {prospect name}, can you keep a secret?

This cold email subject line is a great example of building curiosity about the email content. It forces the prospect to ask questions like ‘what is the secret?’ and ‘can it give me a competitive edge?’ ultimately encouraging them to open it. 

2. {competitor name} is using this, are you?

Keeping an eye on competitors is one of the most important tenets to getting ahead. And so, invoking curiosity in your prospect’s mind or insinuating they missed something is how this cold email subject line helps you. 

3. Are you sure you want to miss this?

This email subject line gets your prospect itching to know what your email is about, while creating a sense of FOMO. It sparks the doubt in your prospect’s mind on whether they can afford to miss something that others might gain from.

4. It’s Finally here and {target audience} are loving it!

What’s finally here? How long have I been waiting for it? And most importantly, are my competitors already reaping benefits? These are the questions running through your prospect’s head as they read this subject line, and their curiosity will have them open the email. 

5. {prospect name} here’s a surprise for you

This subject line achieves two things- personalization and gaining your prospect’s attention. The unique combination will earn you a higher open rate by appealing to the prospect’s curiosity.

10. Follow-up Cold Email Subject Lines

Why Are Follow-up Email Subject Lines Important?

So, your cold email didn’t get opened. Is that the end of the road with this prospect? Are you ready to throw your hat in the ring? You won’t hear a yes from a seasoned SDR. And that’s because you can do one more thing. And that’s sending a follow-up email.

These cold emails are meant to bring your prospect’s attention back to you and give you a second chance at making an impression. It’s also a good way to stress your persistence and let the prospect know you mean business.

Follow-up Email Subject Lines

1. Hi {prospect name}, forgot to mention this

This is one of the best email subject lines for a follow up email. With this you’re building suspense and intriguing the prospect enough to wonder—what did you forget? And could they be missing out if they didn’t read it?

2. Hi {prospect name}, thought you might like this

Offering resources like a case study or whitepaper lets your prospect know you’re working hard to get their attention. This cold email follow-up subject line helps you do just that. And why will they lose out on something that could help them?

3. What would change your mind?

This is a pretty direct cold email subject line that can help you get your prospect to open your email the second time around. By hitting the nail on the head, you’re admitting your first email didn’t play well with your prospect, and are ready to discuss how to get them onboard. 

4. Hi {prospect name}, can’t seem to reach you

This subject line is a great way of contacting your prospect without sounding pushy. Further, by adding their name, you’re adding a personal touch, reducing the chill of a cold email.

5. Want us to stop contacting you?

This email subject line does two things. Firstly, it lets your prospect know they’re in-charge of the conversation. And secondly, it informs them that your aim was never to annoy them, but to genuinely add value.

11. Cold Email Subject Lines With Numbers

Why Are Cold Email Subject Lines With Numbers Effective?

Subject lines with numbers have a higher open rate than those that don’t. Why? Because people don’t read every single word—they scan. And numbers are most digestible. They represent facts, are compact, and enhance scannability. Not to forget, they tend to stand out in the sea of words in your prospect’s inbox. 

Plus, backing your claims with data adds credibility and quantitative benefits. Your prospects don’t need to guess if you’re good, you’re giving them proof that you are. 

Examples of Cold Email Subject Lines With Numbers

1. {prospect name}, X actionable tips for success

Personalization meets numbers in this cold email subject line, effectively killing two birds with one stone. By naming your prospect directly and giving them a decisive number to expect, their cursor is heading to your email.

2. Boost sales by 40%

Value add + statistic = a catchy subject line for cold emails. Use this combination to effectively communicate your email content without revealing all your cards. Here the subject line in your cold email is communicating an important value while backing it up with definitive results, making your prospects curious to learn how.

3. 67% of employees want this

This is not a real statistic, it’s an example of a cold email subject line, but if you were to get this in your inbox, are you sure you’d have been able to fight the curiosity to know what so many employees want? We all look for quick and straightforward ways of improving metrics. And if we find one that is backed by numbers, jumping on it is as good as written in stone. 

4. Power of data: 75% conversion rate

This subject line gives away just enough to make the prospect want more. They’re going to open the email to answer how data helps drive conversion rates? And how can they leverage that? 

5. X simple steps to drive productivity

Your product can help your prospect improve their efficiency. Let them know in your cold email subject line itself. 

Email Subject Line Tester Tools

Okay, so you have 11 types of cold email subject lines and multiple examples to get started. All set, right? Any SDR worth their salt will probably scream a hard NO. 

You must not only keep your subject lines fresh, interesting, and short but also ensure they bypass the spam folder. So, how do you test if your cold email subject lines make the cut? With email subject line testers. 

These tools help you optimize your subject lines by grading them against criteria such as spam words, length, and emotional sentiment. Here are 4 email subject line tester tools that you can use: 

• Refine by Moosend

This tester uses artificial intelligence (AI) to analyze your cold email subject lines and compares it to industry benchmarks. This allows you to gain a fair idea of how your subject line will perform. Further, if it falls short, the tool offers tips to improve and boost your open rate. 

• Email Subject Line Tester by CoSchedule

This platform scores your cold email subject line out of 100, depending on how effective it is. It analyzes the subject line on metrics such as character count, emoji count, and how it will appear on desktops as well as mobiles. 

• Send Check It

This platform compares your cold email subject line against 100,000+ emails sent by other marketers. And then scores it based on metrics like scannability, reading grade level, spammy words, and the like. 

• Email Subject Line Grader by Net Atlantic

This tool analyzes the impact of your cold email subject lines in terms of character count, emotion, and power of words. Based on this, it tells you whether your subject line is too generic and offers suggestions on how to improve. 

Amp up Your Subject Lines

These 11 cold email subject lines and their examples are sure to help you drive open rates. However, as effective as they are, some subject lines will perform better than others. How do you identify those? With A/B testing. Also known as split testing, this method helps identify your top performers by comparing two or more versions of the same cold email subject line and tracking their performance. 

There’s no sure-shot way of guaranteeing the success of your cold email subject lines unless you find what works for your prospects—is it funny, curiosity-provoking, or a numbers game? Start testing with these examples and find out.

FAQs