How to craft the best email subject line with a keyword checker

You’ve developed your email with interactive, bold content that is sure to wow your subscribers into action. You even segmented your email list to add additional personalization for each individual subscriber. You quickly type in a subject line, hit send, and boom! Sit and watch the clicks come through—right?

By all accounts, you included email marketing best practices that should result in high engagement. However, you might've made one fatal mistake—you missed the opportunity to create a subject line that truly converts.

Your subject line is the first impression a subscriber has of an email. With people receiving hundreds of emails a day, you need to develop a subject line that stands out in a crowded inbox and entices someone to click on yours. While sometimes brand loyalty is enough, a strong subject line provides your campaign the extra push to receive valuable open rates that will convert subscribers into customers. 

One of the best ways to gut check this is using an email subject line keyword checker to ensure your hard efforts of creating an impactful email don’t go to waste. While there are many ways to go about this, we'll be exploring why a keyword checker is important how to successfully use one for your next email marketing campaign.

What is a subject line keyword checker and why should you use one?

If you struggle to achieve high open rates, it’s possible that your subject line isn’t landing. For some marketers, creating witty and clickable subject lines can be a challenge—which is where an email subject line checker can come in handy.

These tools analyze which keywords are more effective, how to elicit an emotional response, and even warn you against spam triggers. After all, an email marketer’s worst nightmare is being tossed in the dreaded spam folder. Lastly, a subject line keyword checker will give your phrase an overall grade on how clickable your emails are, which will help you gauge your open and click-through rates.

A keyword tool is invaluable and savvy email marketers should include one in their arsenal to build a dynamic email marketing strategy that converts

Recommended email subject line keyword checkers

Now that you know how a keyword checker can impact your email campaigns, let’s take a look at some of the tools you can utilize. While there are many on the market, it’s important to test a few to decide which garners you the most engagement. 

1. Email Subject Line Grader by Net Atlantic

As a free tool, Email Subject Line Grader takes a look at how effective your content will be in terms of word count, copy, and balance. You will receive a numerical grade along with suggestions on how to improve it. If you need a higher word count or more action—this tool will tell you.

As a free tool, Email Subject Line Grader takes a look at how effective your content will be in terms of word count, copy, and balance.

Source: Net Atlantic

2. Spam Check by Postmark

After you’ve spent time developing the perfect email, you don’t want it to be sent directly to the spam folder and never seen by your subscribers. By utilizing Spam Check, it will tell you if your subject line, preheader text, or email message will trigger any spam filters. 

3. SubjectLine.com

This tool will rate your overall effectiveness and tell you where you can improve. It’s all based on a point system. For example, -15 points for not containing a sense of urgency, +3 points for including a number, etc. With these actionable tips, SubjectLine.com will help you get a perfect score for your next campaign for free.

With these actionable tips, SubjectLine.com will help you get a perfect score for your next campaign for free.

Source: SubjectLine.com

4. Emotional Marketing Value Headline Analyzer by The Advanced Marketing Institute

As humans, we’re more likely to connect with content that creates an emotional response. With the Emotional Marketing Value Headline Analyzer, you’re able to understand if your subject line appeals to the empathetic or intellectual side of your subscriber’s brain. Depending on your email’s content, you may want it to appeal to one side over another.

How to use a keyword checker to build the best subject lines

Once you have figured out which tool you want to use, it's time to get the most out of your email subject line keyword checker. For all of the tools listed above, you simply copy and paste your intended phrase, click submit, and analyze the improvement suggestions. Improvement suggestions may include:

  • Adding or removing to the word count

  • Avoiding spam triggers like “free”

  • Including numbers and other buzzwords

These opportunities are important to pay attention to and offer great advice on how to optimize your subject line for results.

We always recommend testing multiple subject lines in the keyword checker to see which versions will be the most effective. This could be the difference of removing a percentage sign or adding an urgent word like “now.” 

If you develop two subject lines that are equally impressive, you can split A/B test them to determine which harnesses the most engagement. With Emma, you can try out two versions of a subject line to a smaller sample audience. Once you can determine which performed the best, it will be delivered to the rest of your audience.

With Emma, you can try out two versions of a subject line to a smaller sample audience. Once you can determine which performed the best, it will be delivered to the rest of your audience.

Source: Emma

If you’re wondering which subject line elements perform the best, let’s take a look at a few best practices you can utilize when crafting your subject line. 

Add personalization

Personalization increases the likelihood of your email being opened by 26%. Why? Your readers want to feel like you care about them individually. You can utilize merge tags in your email subject line to include the subscribers first name, or include their past purchase history. 

Personalization increases the likelihood of your email being opened by 26%. Why? Your readers want to feel like you care about them individually—not just another fish in your net.

Source: Gmail

Take this example from Panera. Not only is this subject line utilizing the subscriber’s name, but it’s also offering them a way to save money with a rewards program.

Ask question

If you’re looking for more engagement within your actual email, asking your readers a question in the subject line is a great way to receive action. These emails can ask your customer feedback which not only provides you valuable information but shows your customers that you care about their overall experience. You can also use questions to provide news or updates about your company. Questions will grab your reader’s attention and direct them back to your brand.

If you’re looking for more engagement within your actual email, asking your readers a question in the subject line is a great way to receive action.

Source: Gmail

If you have an Alexa, this email is a great way to learn about any new updates. By asking a question in the subject line, it’s straight the point and offers a bit of mystery. 

Solve problems with "How to"

Add value to your subscriber’s inbox by providing them the answers to their questions. ‘How to’ email subjects lines work because it’s setting up expectations about the email’s content, and hopefully, is a topic that’s important enough to your subscribers for them to click. 

Add value to your subscriber’s inbox by providing them the answers to their questions

Source: Gmail 

This example from Clean Plates illustrates how subscribers can live a more healthy lifestyle—which appeals to a wide variety of audiences.

Add a sense of urgency

Subscribers often have FOMO—fear of missing out—on a deal that’s not going to be around forever. Creating a sense of urgency in your subject line helps entice the reader to open your message because they won’t want to miss out on what you’re offering.

Creating a sense of urgency in your subject line helps entice the reader to open your message because they won’t want to miss out on what you’re offering.

Source: Gmail

Thrive Market utilizes buzzwords ‘last’, ‘final’, and ‘mega savings’ to really drive home the fact that a sale is happening and it’s ending soon. With these words, subscribers are most likely to click on the email to discover what deals they could be missing out on.

Optimize with character counts

With shorter user attention spans, even your character count can make a difference in your open rates. Seven words seems to be the sweet spot. 

According to Marketo, 7 words—41 characters—is your best chance of getting your emails opened.

Source: Marketo

Use emoji’s

Emojis are a great way to have a little fun with your subject line and grab your subscriber’s attention with a creative flair. Choose a relevant emoji that relates to your content, but ensure you test it carefully across different operating systems. For example, emoji’s do not appear the same on iPhones and Androids.

Emojis are a great way to have a little fun with your subject line and grab your subscriber’s attention with a creative flair.

Source: Gmail

The double palm trees in this email from Joss & Main draw a reader’s attention immediately to the subject line. It’s creative, eye-catching, and on theme with an outdoor seating sale.

Wrap up

By utilizing an email subject line keyword checker, you’re able to test and create phrases that will make the most impact in your subscriber’s inbox. Your subject line is the make-it-or-break-it point in your email campaign and it’s crucial to develop text that evokes your subscribers to take action and convert.

When utilizing your keyword checker, ensure you:

  • Use personalization

  • Ask a question

  • Solve a problem

  • Build urgency

  • Make it fun

With these practices in mind, crafting the perfect subject line will be a breeze. The keyword checker will make it easier to develop messaging and gut-check your text to ensure you boost engagement rates.

Are you ready to start crafting creative subject lines and press send? Try a free demo of Emma today to learn how this platform can help streamline your email marketing strategy.

About the Author

Emma is an email marketing platform that gives you all the tools you need to send campaigns that really connect with your subscribers. With our

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