How to use an email subject line generator to create great copy

An email subject line has one job: to get the email opened. According to a SuperOffice study, almost 34% of recipients said that they opened an email because of the subject line.‍

But writing copy that gets someone to open the email you’ve sent is easier said than done. A recent Smart Insights study found that less than 17% of emails are opened.‍

So how do you write a good subject line? An email subject line generator like Copy.ai’s Catchy Email Subject Lines tool is a great way to get started. If you’re not feeling creative or you simply don’t know where to start with your writing, our free tool can help you kick-start the process.‍

Here’s how our email subject line generator works:

Step 1: Enter details about your brand and promotion

Once you’ve entered the Copy.ai application, you can find the Catchy Email Subject Lines tool on the Tools list. Click to open it.‍

You’ll now see the Catchy Email Subject Lines interface, which is where you’ll be inputting all of the information that’s relevant to the email you want to send—namely, your product/brand name and a description of your product.

Don’t hesitate to include a lot of information about your product or promotion. These details help our email subject line generator provide relevant copy suggestions.

From there, pick a tone of voice (friendly, persuasive, witty, etc.) that corresponds with your brand or product.

All set? Click the “Create Copy” button and let the tool work its magic.

Step 2: Browse through the generated ideas

After just a few seconds, the email subject line generator will generate a list of ideas for you.

Have a look at the suggestions, and see if any of them catch your eye. If you want the tool to generate more subject line suggestions, click the “Make More” button. The tool will generate another set of new subject lines and add them to the list.

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Want to move these subject line suggestions outside of Copy.ai? Click the “Copy All Results” button (see above) to copy all of the suggestions to your clipboard and paste them in another spot (like a spreadsheet).

Step 3: Find ideas you like and save them

If you see an email subject line you really like, click the “Save” button below it. The tool will send the line to the “Saved” section. Click on the “Saved” tab to see all of your favorite subject line ideas from the tool.

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If you’ve had a change of heart and no longer like the subject line you’ve saved, click the “Remove” button to get rid of it.

Step 4: Generate more ideas based on your favorites lines

If you’re stuck in writer’s block mode, click the tool’s “More Like This” button. Please note that the “Make More” and “More Like This” features are not the same. “Make More” adds more subject line options to the originally generated list. The “More Like This” feature generates additional copy based on a single subject line. Here’s how it works:‍

Click back on the “Create Copy” tab and find a subject line you think is interesting. When you click the “More Like This” button below it, the tool will generate additional copy based on that subject line.

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Use these suggestions to write your own subject lines, or you could use the text to start creating the body of your email.

Step 5: Refine your subject lines based on best practices

Remember, none of the generated subject lines are set in stone. Play around with the wording by simply clicking on the line and editing it to your liking. Consider how you might adjust each line to engage your unique audience.‍

Here are a few tips for making subject lines click-worthy:

• Ask a question: Questions pique curiosity, and curiosity is what makes people open and click through emails. In a recent Yesware study, subject lines that were questions had 10% greater open rates than average.
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• Personalize the subject line: Stand out from the crowd by creating personalized email subject lines that show recipients you’ve done the legwork to learn something about them—even if it’s just their name. According to a Get Response survey, personalizing email subject lines can increase your open rates by up to 5%.
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• Pay attention to length: There’s a word count next to every subject line in Copy.ai. A Marketo study says 41 characters or seven words is the “sweet spot,” while Mailchimp recommends no more than 60 characters or nine words, emojis included.
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• Offer the recipient something: Provide something valuable to entice your reader, like exclusive content or a free product. According to a study performed by DMi, recipients respond best to "free product" offers, which generated 275% more opt-ins than campaigns that offered a percent off first purchase (POFP) incentive.
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• Be honest: Don’t write a false subject line just to get an open. Make sure your subject lines match the content of your emails, particularly if you're emailing about a specific topic or selling a certain product. In a survey performed by Edelman, 81% of consumers said that they need to be able to trust the brand in order to buy from them.

Step 6: Pick your favorite subject lines and A/B test them

There is no surefire way to create a killer subject line, even with the best copywriters. Use an email marketing app to A/B test your email marketing campaigns to see what works and what doesn't.‍

A/B testing is a simple two-step technique that's used to optimize email content conversion rates:

1. You pick two different email subject lines, sending one to segment A of your audience and the other to segment B.
2. You track KPIs (email open rate, click-through rate, unsubscribe rate) for both variants.

Based on this performance data, you'll know which subject line converts better and should be sent out to a wider audience.‍

If you have more than two subject lines you’d like to test, no problem. You can run a multivariate test with as many variants as you want.‍

We recently sent out five variants to 10% of our email list using a tool called Customer.io. After one hour, it became clear that Variant One had a higher open rate than the rest. As a result, the remaining 90% of our email list received an email with Variant One.

If we hadn’t A/B tested our subject lines and had just run with Variant Five, our second-best email subject line, we would have had 12,000 fewer opens!‍

It took only a few minutes to generate and tweak these additional variants using our email subject line generator, and it had a massive impact. According to Litmus research, nearly 90% of businesses conduct A/B tests on their emails, focusing mainly on subject lines, calls-to-action, and send times.

Use an email subject line generator to evolve your approach

Finding good email subject lines that work best for your audience is a process that truly never ends. As your audience grows and changes, your sales emails that had great open rates a year ago might be bombing now.‍

AI-powered free email subject line generators are fantastic tools that help email marketers and other content and digital marketing professionals stay creative and experiment with subject lines. They are easy and intuitive to use and can make a process that many marketers and copywriters consider tedious kind of fun and exciting.‍

Looking for more tips on how to write a great subject line to increase open rates and automation your email workflow?

Read our detailed email subject line guide and lean more about our AI workflow automation.

Try using our AI writing generators today!

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