101 Best Cold Email Subject Lines To Increase Email Open Rate

101 Best Cold Email Subject Lines To Increase Email Open Rate

In this article, you will learn what to place in the subject line of a cold email. Let’s dive right in without wasting time.

But before that, do you know this fact? On average, people receive around 50-200 emails per day. However, the average open rate is low. You might think that it all depends on the body content.

But if no one opens your email, how will anyone read the body content? In a way, cold email subject lines emerge as the top strategy for a successful campaign.

Table Of Contents

What Is A Cold Email?

A cold email is an email you send to your prospects with whom you don’t share any relation. The sole purpose of cold emailing is to pitch the offer and generate leads. The approach to send cold emails has emerged significantly.

Importance Of Cold Email Subject Lines

The most important thing before crafting an email is to think about your prospect’s journey.

How does it start?

The moment your emails reach their inbox, the subject line becomes the deciding factor.

How does your body content matter if the prospect has not opened your email? Keep that in mind ideal email subject lines are not easy. 

It helps to increase your sales outreach and boost your open rate.

Later, I will teach you how to write a cold email subject line.

Use Cold Email Subject Line Generator

But why?

You can use this tool to generate subject lines to get started.

You might even use some but the main purpose is getting ideas.

Use a free subject line generator if you do not want to invest upfront.

You can do so in just two steps:

Step 1: Enter the service you provide and the recipient company

the main page of salesblink's free cold email subject line generator

Step 2: Click “Generate Subject Lines”

subject line generator for oyo catering

Easy, right?

Best Practices For Crafting Cold Email Subject Lines

Here are some best practices to craft the subject line for cold emails and boost your open rate.

1. Keep subject lines short

Long subject lines do work in a few cases, but it depends on which device they open.

Traditionally, sales-related emails used to have longer subject lines. But with people reading emails from mobile, some of the characters get cut off from the mobile.

The ideal length of your subject line is between 36-50 characters. Try to keep your subject lines precise and short as it fits the mobile screen.

2. Don’t use clickbait Subject lines for Cold Email

70% of people send their emails to spam after reading the clickbait subject lines. The best possible way to avoid your email from reaching spam is to fix your subject line with realistic goals.

Don’t use spam trigger words like “double your income,” “100% free”, “free leads,” and many more.

There is no point in getting your email open if it breaks the trust of your prospect. If you want your prospect to feel good with the interaction and take the desired action, try not to use such words in subject lines for cold email.

3. Personalize the subject lines

According to stats, emails with personalized subject lines are 22.2% more likely to open.

You have to craft something, which encourages them to open the email.

Use the following tips to personalize your cold email:

Tip #1

What better than adding their name to grab that attention.

Using the prospect’s name in the subject is a good way to capture his or her attention.

Prospects will feel valued upon spotting their name in the subject line and opening such emails.     

Tip #2

Keep the interests of your prospect in mind when sending them an email.

Learning about their interests and using them in email subject lines is a great way to add a personalized touch.

Your email subject line should make recipients feel that they can find something relevant in the email body.  

Tip #3

Go the extra mile and wish prospects on their birthdays and anniversaries. The response rates for these kinds of emails are generally high. It feels good when someone wishes you on a special day.

You can very well add a promotional offer along and still get a good response.

Tip #4

Another way of using personalization is by keeping the location of the prospect in mind while sending an email. Localization ensures that what you are offering is relevant to where they stay. You can’t afford to send them subject lines like ‘Offer on raincoats’ when it is peak summer in their part of the world.

4. Offer something enticing

When it comes to engaging the audience and driving their curiosity, you need to offer something which grabs their attention.

It should be something that adds value because the email recipients will click open the email only when it has something in it for them.

It can be some a discount or special offer. Give the prospects a reason to invest their time into reading the email. 

5. Use FOMO 

Make them feel as if they are missing out on something. Try to play it with human psychology, like creating a sense of urgency.

The FOMO tactic to make your subject line stand out works well. Such emails that create a sense of urgency have a higher open rate when compared to others.

Something like – “Only 5 T-shirts left” can do the trick.

6. Keep Testing

Unfortunately, there are no fixed standards to craft cold email subject lines. No particular format is available. 

It would help if you keep testing again and again to strike the deal. Find out what resonates best with your target audience and work accordingly on your subject line.

7. Experiment a little 

To find out a subject line that works, you have to experiment a little, which can take time. If you happen to find a subject line that works, it doesn’t mean that you can sit back and relax. You still have to test different subject lines. Eventually, you would understand what kind of subject lines are working so that you can stick to them most often. 

8. Make use of persuasive words

Words are immensely powerful as they can substantially impact the recipient. Certain words make the recipient want to click open an email. Humans are emotional and curious beings and are not able to control themselves. When you use certain persuasive words, prospects can’t stop themselves from opening your email. 

Words like ‘astonishing’, ‘banned’, ‘insane’, ‘unique’ and ‘secret’ arouse curiosity while ones like ‘best’, ‘certified’, ‘endorsed’, ‘expert’ help build trust. 

9. Use open-ended questions

You can ask open-ended questions in the subject lines as it will successfully draw the attention of prospects towards your email. Are you wondering why that happens? The brain gets stimulated when a question is put forth, and that is why it is a good tactic to ask a question. 

It can be anything they can relate to. But make sure that they are the right ones. Such as ones related to the pain points faced by prospects. The timing of the email is also essential if you are seeking an immediate response.

This is how to write the subject line of a cold email to boost the open rates.

101 Cold Email Subject Line Templates

Take a look at different cold email subject line templates and communicate like a boss.

When You Have A Mutual Connection/Recommendation

This approach makes your cold email subject line a little warmer. The recipient will most likely open it, assuming that the information may be relevant to them.

Hi, (Receiver name)! We met at a conference in Delhi

Anita Wagh told me that I could write to you

Mutual connection with <name>

Liked attending <recent event>

Saw your comment on <Blog name> 

A friend of <name of mutual contact>

Hi <prospect’s name>. We met at <name of the conference or event>

BTW, <name of mutual contact> asked me to contact you

Personalized Subject Lines

Try to drive their attention with a layer of personalization- name, and location. 

Here are such cold email subject line examples:

We set the stage for {Company Name} to be the talk of {Location}

<First name of prospect>, <pain point>

<Name of the prospect>, thanks from <Your business name>

Hi <prospect’s name>! Do you know about <Your product of service>?

<Prospect’s name>, do you want to increase revenue?

I made a custom report for you, <Prospect’s name>

Special savings for <Prospect’s name>

Have a look <Prospect’s name>

What to do with $100, <Prospect’s name>?

Create A Sense Of Urgency 

Try to create a catchy subject line for cold email that creates a pressure of urgency and a sense of missing out on something.

The offer is valid until noon

Your competitors effectively use these 11 hidden industry tips (but you don’t)

There’s just one week left – Watch me on TV! 

Last few seats available

2 days left for <the event>, free for a call?

Another week to go for <target>

Curiosity Subject Lines

Humans are curious, and when we get incomplete details about something, we have an urge to know more. You can tap the potential of this nature in email subject lines. The aim is to arouse the curiosity of prospects.

Don’t open this!

Last chance to see what this email is about

Disgusting business ideas

Unwrap your surprise

Monkey habits to get rich

You are invited

It has arrived

Is it your lucky day?

What have you been waiting for?

Short Subject Lines

At times a few words can make a better impact than a whole sentence. They look more casual too. Here are a few examples:

Request to connect


Moving ahead?

My mistake!

Your Priorities


Sloth Subject Lines

One central human tendency is to avoid doing work. People don’t want to walk on a challenging route. That is why we all like it when there is a shortcut. If you apply this to cold email subject lines, you can get desired results.

Ideas to grow your email list 10 times faster

Email templates ready to steal

5 Hacks to triple revenue

Checklist to create opt-in form quickly

Ready-to-use blog post ideas

Meeting Request

Here are a few subject lines that work well when you want to schedule a meeting with the prospect. Make it as relevant as possible, and do your research beforehand. 

Hi < prospect’s name> Do you have 5 minutes?

Want to show you something next week

Have time on Wednesday?

Meeting request – You and me!

Can we meet, < prospect’s name?

Would you like to connect? Let’s meet at <cafe name>

Follow-Up Emails

Writing a follow-up email, although necessary in many cases, can be very tricky sometimes. Just use some of these catchy subject lines in your subsequent follow-up campaign-

Hi, this is [Your Name/ Company Name] again! Just in case you didn’t receive my previous mails

Thanks for your time,[Recipient Name]!

Let me know if I am too persistent.

Let’s make a plan

Still thinking it over. This might be of help

Just looking out for you

You left your things at our place

Open-Ended Question Email

It’s a solid way to spark conversation and start building a relationship with the prospect.

What’s next for [Company Name]?

Tech question for <prospect name>

Do you make these mistakes?

Did you know <company name> was doing this?

Do you face this challenge?

Retargeting Emails

You can send such emails when the prospect fails to complete an action or doesn’t seem to move ahead in the sales funnel.

Hey, did you forget something? Here’s 10% off.

The price dropped for an item in your cart

< prospect’s name>, your account is on hold!

Here’s my personal email

Did you know about some of these new features?

Pain Point Questions

The most effective way to ask the right question is by asking the appropriate question at the right time. Try to ask politely. If the question refers to the user, the prospect will start the communication.

Hi,[Recipient Name]! Are you tired of hiring people who quit in a month?

{Recipient Name}, will you let me ask you a question about…?

A 5-step plan for your hectic week

Stop wasting money on <product or service>

Save space with <product or service>

<Prospect’s name>, solve your <issue> with <product or service>

Secret Word

We want to share some secret words that bring fantastic results. According to research, emails that contain videos have better click-through rates. Add the word “video” in your subject line only if it has any video link. 

A demo video demonstrating how our sales-boosting product works

We are almost sure you want to have a quick look at this video tutorial

This video with seven email marketing hacks will help you improve your results.

Find out how to skyrocket sales with [Product] in a quick video

Humorous Subject Lines

Humour is cherished in every way. After all, humor is a considerable attention grabber. But remember that humour can be dangerous if perceived in the wrong way.

Try to create funny subject lines that capture your audience’s interest. Choose your jokes carefully that fit right at the time.

Did you see that funny display last night?

Your Hotstar password?

I got the good stuff. Hit me up anytime.

Hello from the other side…

Are you ok?

Where is the love?

We like being used

Great, another email!

No, not shutting shop yet!

Value Addition/Benefit Proposition

Writing cold email subject lines with benefits that your product/service can offer is the best way to grab that attention.

Convey a clear advantage to the prospect and see an increase in open rates. Unless and until an email benefits prospects, they would not click it open. 

These subject lines are an effective strategy when you get the timing right.

The perfect opening to a case interview.

<Recipient name>, inch towards success in Banking exam.

Brand new HR strategy

No more long meetings

Get 20+ hours of extra selling time

Earn record-breaking revenue with ><product or service>

No need for signatures anymore

A quick idea to improve <topic>

Save <amount or percentage> on <product or service>

Pick up sales fast with <product or service> 

Congratulatory Subject Lines

Congratulating the prospect for a recent accomplishment can be an easy way to start the conversation. Such emails have a higher open rate. 

Congrats on the new collaboration

-Congratulations on your book deal

Congrats – just saw you featured on <website>

Your presentation was terrific at <event>

Way to go! Noticed your new <product name>

Congrats on your new launch


Subject lines of cold emails are a tough nut to crack. But with these ideas, you can reach your goal.

The correct subject line will help you drive traffic and boost your open rates. With a significant increase in the number of cold emails, you need to establish a way to stand out. These are some tactics that have worked well for most marketers.

Thus, pay attention to these tactics above and test what can bring you excellent results.

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