A creative subject line can make your emails stand out in your subscriber’s inbox. Capturing your subscribers’ attention and getting them to open your emails is winning half the battle. However, there is no guarantee that email marketers can always come up with the most suitable subject line. This is where the free email subject line generators come in. These subject line generators can create dozens of compelling and click-worthy subject lines within a matter of seconds. Even the most experienced email marketers use these generators once in a while. Here are the top 5 email subject line generators to help you create fitting subject lines for your email campaigns. 

5 free subject line generators 

Active Campaign allows the user to create subject lines for their emails using keywords. First, the email marketer has to choose the keyword category from the drop-down list. Topic, benefit, and pain points are the three categories mentioned in the list. Now, enter the keyword and click on “Generate subject lines.” The suggested subject lines are displayed just below the action button. Active Campaigns subject line generator can only display 4 results at a time. But, it also offers the option to generate more subject lines. You can use the copy button on the results page to directly copy them to your clipboard. Furthermore, Active Campaigns offers a detailed guide to creating the best subject lines for your email campaigns. 

Top 5 free online subject line generators for your email campaigns

If email marketers want to get innovative subject lines, they should head to Encahrge. It uses advanced AI algorithms and the power of GPT-3 to produce subject lines for your email campaigns. You only have to enter the company’s name, the tone, and the purpose of the email to get the subject lines. Using these details, the GPT-3 protocol scans the internet and creates very human-like subject lines. In addition to that, the AI tries to understand the lingo of your industry before creating the subject lines. On the same webpage, Encharge offers 15 free subject line templates to help you create personalized subject lines for your company. 

Top 5 free online subject line generators for your email campaigns

Reply’s subject line generator is somewhat similar to that of Active Campaign, but it offers different formats for separate categories. Clicking on the generate button starts displaying the list of various subject lines. However, for some categories, the auto-generated subject lines might not be coherent enough. Applying some minor edits to the auto-generated subject lines can fix these errors. You can also use their export feature to download all the listed subject lines in a spreadsheet format. 

Top 5 free online subject line generators for your email campaigns

Keap’s subject line generator creates high-quality subject lines for your sales and marketing email campaigns. In the first step, it will ask you to select the type of message you want the subject line for. You can choose from newsletters, re-engagement, follow-up, registration, promotion, and resources options. Then, you have to enter more details about the recipient. Keap asks you to enter the results that your readers are expecting and the pain areas they want to avoid. You also need to enter the keywords or the interest category. Click on “generate subject lines”, and it will instantly give you the results. To make it convenient for the marketer to access these subject lines, they have included a feature that emails you all the results.

Top 5 free online subject line generators for your email campaigns

Salesblink’s online email subject line generator is much simpler compared to others mentioned in the list. The marketers just have to enter the service they provide and the names of the recipients. The algorithm will handle the rest and create effective subject lines for the email campaigns. However, some of the subject lines created using this generator contain spammy words that might hamper your deliverability rates. Therefore, always clean up the subject lines before sending them out to your subscribers. 

Top 5 free online subject line generators for your email campaigns

Tips and tricks to make your subject lines more interesting 

  • Use personalized email subject lines 

Try adding the email recipient’s name or location to the subject line to make them more impactful. Personalization is a proven method of increasing the open rates of your emails. When combined with segmentation strategies and automated campaigns, they can drastically increase click-through rates. Email marketing firms use merge tags to easily add little touches of personalization to their subject lines. 

  • Keep them short

There are a few downsides to writing long subject lines. To begin with, most email clients will clip the subject line after the first few words. On top of that, longer subject lines can trigger the spam filters and affect your sender’s reputation. Hence, keep the subject lines concise and use a limited number of words.

  • Avoid using punctuations 

Again, adding too many punctuation marks in your subject line can make your emails look like spam. You should also avoid using special characters for the same reason. 

  • Test your subject lines 

Always test your subject lines before sending them to your entire email list. Use A/B testing to gauge their performance and make the changes accordingly. You can also run a multivariate testing campaign to see how these changes in your subject line are affecting the open rates of your emails.


These generators are pretty handy when it comes to brainstorming ideas for your email campaigns. If you are still struggling with creating attention-grabbing subject lines for your campaigns, you should hire an email marketing firm to make things easier for you. The firm will not only create stunning subject lines for you but will also extensively test them for effectiveness.