6 Free Subject Line Tools to Increase Email Opens

Subject lines have long been proven to influence whether emails are opened, deleted, or sent to the spam folder. Here are 6 free tools to help you create email marketing subject lines that work.

Tools for Improving Email Subject Lines

  • Headline Analyzer
  • TestSubject
  • Subject Line
  • Email Subject Line Tester
  • Capitalize My Title
  • IsNotSpam
  1. Headline Analyzer

This CoSchedule tool assesses the strength of your subject lines (and blog post titles). Common, uncommon, emotional, and powerful words are considered. Not to mention headline sentiment, keyword usage, length, and key idea placement.

The Headline Analyzer is great for comparing the strength of multiple subject lines in one session. Changing options does not delete previous ones. Rather, the Headline History section lets you see all scores at a glance and zoom in for more detail.

  1. TestSubject

This ZURB tool is only for mobile. It also shows your sender name and pre-header text on the most popular devices. Before you send your emails, you can use this information to improve their effectiveness.

Because TestSubject only looks at the subject line and not the email content, it’s best used in conjunction with another tool that looks at the content.

  1. Subject Line

This tool is as simple as it gets. You enter your subject line and get a list of its good and bad points. Each quality element of your subject line is assigned a point value, and you receive a score out of 100. Lose 15 points for a lack of urgency, gain three for using the second person POV.

Subject Line is so valuable because it is based on over 3 billion email messages (and counting). They’ve been tested on over 800 different rules and factors, so you can bet the creators of this tool know what works.

  1. Email Subject Line Tester

Email Subject Line Tester, also by CoSchedule, is for email subject lines. It, too, has Headline History and shows previews of your subject line on various devices.

But the rest of the analysis isn’t. It reports on words that increase or decrease email opens, case, number of words, and length. Each section contains brief but valuable research-backed suggestions for improvement.

  1. Capitalize My Title

This is useful if you use a particular style of capitalization in your subject lines (e.g. AP, Chicago, etc.). The tool is quick and simple to use. But Capitalize My Title also provides capitalization guidelines so you can avoid using the capitalization checker.

  1. IsNotSpam

IsNotSpam alerts senders if their emails trigger spam filters. Simply send an email to the designated address to view your report. Checks It will highlight words or phrases that may cause your message to be spammed.

You’ll get insights into your entire email message as well as your subject line.

In Conclusion

As you can see, your subject line’s appearance, content, format, and more can all be tested. By doing your homework before sending a message to your subscribers, you increase your chances of success. Try out the above tools and see how you can combine them to write more compelling subject lines.