10 Best AI Email Subject Line Tools and Testers

Subject lines are super important to boost open rates, and writing a perfect subject line can take a lot of effort and time. Lucky for you, there are a lot of artificial intelligence tools that you can use to generate AI email subject lines that are compelling and highly converting. In this guide, we will discuss some of the best AI email subject line generators.

Table of contents

• How to write an effective AI email subject line?

• Write AI email subject lines

  • 1. Encharge
  • 2. YAMM
  • 3. Mailmunch
  • 3. Copy AI
  • 4. Wordkraft
  • 5. Storylab

• Test email subject lines

  • 1. Mailmeteor
  • 2. CoSchedule
  • 3. Ortto
  • 4. Refine by Moosend

• Takeaway

How to write an effective AI email subject line?

AI tools like email subject line generators can greatly help generate relevant, personalized, and catchy email subject lines. How they do it:

• Most AI email subject line generators would ask you to feed some information or context about the email.

• You can provide information like the tone, type of email, your name, recipient's name, keywords, etc.

• After you have added the information, the AI email subject line tool will analyze and understand the context to generate multiple numbers of AI email subject lines.

• You can edit the subject lines and ensure they resonate with your goal or purpose, as AI might only sometimes be able to generate creative copies.

Many AI subject line generators can be used as an extension to your email software, while some are not, for those you need to copy and paste.

Write AI email subject lines

Below is the list of free AI email subject lines created with AI-powered tools and how you can use them for your emails:

1. Encharge

The Encharge AI Email Subject Line Generator is a tool developed by Encharge that utilizes AI technology to generate compelling and unique subject lines for emails. It asks you about the following information to generate subject lines:

• The goal of your email

• Your company/product name

• The tone of the email

Here's how I generated AI subject lines informing the users about the ongoing sale at Microsoft using Encharge. It generated these email subject lines:

This is a free-to-use tool that does not require any login.

💡Related guide: 11 AI Copywriting Tools to Save You 100+ Hours of Work

2. YAMM

YAMM subject line generator is an easy-to-use, free, and no-login AI email generator that helps you write engaging email subject lines by just providing it the email body or even a phrase, and it generates 5 creative subject lines for you to use.

I used YAMM to generate subject lines for a new local shop offering discounts on their first visit. These were the results:

This tool is free to use.

3. Mailmunch

Mailmunch is a lead-generation email marketing platform. It provides an AI-powered email subject line generator that helps you write engaging email subject lines in seconds. You need to provide information like:

• The goal of your email

• Your company name

• The tone of the email

For a trial, I tried generating some AI email subject lines, reminding the customer of their subscription renewal. It helped me generate the following subject lines.

The tool is free to use.

3. Copy AI

Copy AI is an easy-to-use copy-generating tool that can help you write content quickly. You can use its AI chat feature and ask to write an email subject line about any given topic. It requires login to generate the subject lines.

In this case, I asked the AI chatbot to generate catchy subject lines about a checklist for mothers taking their babies out for the day. It helped me generate around 20 creative AI email subject lines to choose from:

The tool is free to use.

💡Related guide: 15 Best AI Email Writers to Write Email 10X Faster

4. Wordkraft

Wordkraft is an AI tool that helps you write blog posts, research keywords, paraphrase, generate images, etc. It has a subject line generator that can generate email subject lines in a blink of an eye.

I generated a few email subject lines on Mailmodo's interactive emails. It generated a few for the first time. As I wasn't satisfied with the result, I tried to generate more, but it gave me almost the same results. It just changed a few words, which weren't very useful.

This tool requires login to use and comes with a free trial with limited word usage.

5. Storylab

Storylab is an AI content creation tool that helps you create engaging and high-quality copy at scale. It has in-built tools like AI email subject line generators that can help you write creative email subject line copies.

I generated a sales email subject line using Storylab, and these were some results. Although it generated 4 email subject lines, I found them generic and not so engaging.

This tool gives you only 5 free runs. You need to upgrade to a paid plan for unlimited runs.

Test email subject lines

Your job continues beyond just writing email subject lines using AI tools. You need to test your AI email subject lines with AI to see which works the best. Here again, AI tools can be leveraged to analyze and test the subject lines and identify the negatives and positives of each subject line.

Here are some AI email subject line testers that you can use to test if your subject lines are effective:

1. Mailmeteor

Mailmeteor is an email marketing platform that can help you send personalized mass emails and track them. It also provides an email subject line tester that provides a score for your email subject line and also suggests alternate subject lines that you can use.

I tried testing a sample email subject line, and it gave me a score of 57. It's not too bad?

This tool is free to use.

2. CoSchedule

CoSchedule is an email subject line tester that helps you get a subject line score, see the words that increase or decrease the chances of opening the emails, check the word, character, emoji, and number count, and gives a preview of your subject line on various devices.

I tested this subject line, which gave me a great in-depth result.

3. Ortto

Ortto is a CRM platform that streamlines your marketing campaigns and customer journeys to yield better results. It provides a free email testing tool that you can use to test the effectiveness of your subject lines. It also provides alternatives that you can use.

4. Refine by Moosend

Refine is an email subject line tester that helps you uncover the predicted percentage of your email being opened with the subject line you provide. It also gives you actionable suggestions that can help improve your subject lines.

Here's what I got!😎

You can also use many AI email marketing tools that can extend your capabilities as an email marketer. These are much more powerful and can help you boost your open and conversion rates.

Takeaway

These tools can help generate effective AI email subject lines and test them before you hit send. Remember that all these tools are AI-powered, but AI can misunderstand and make mistakes, so always proofread your subject lines rather than copy and paste.