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Free AI subject line generator

Looking for faster and more reliable ways to write subject lines that lead to more opened emails? Omnisend’s free AI email subject line generator can help create high-converting options in seconds, without requiring any sign-up.

All you have to do is enter a bit of information about the email you’re writing, and our subject line generator will come up with a list of subject line suggestions, including emojis. If you don’t like the initial suggestions, just hit “Give me 5 more options”.

What is your email about?

Give us at least 5 keywords and a quick idea (30-50 characters) about the email you want to send.

Give our AI about 15 seconds to generate the subject lines for you.

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Your personalized subject lines are ready!

Here's a set of freshly generated subject lines that our AI has crafted for you. Use them to make your emails stand out in any inbox.

Subject line suggestions

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How to use the AI subject line generator

1. Enter your email details. Try to be specific and descriptive — mention the email and campaign type, what kind of tone you’re looking for, and who your audience is.

2. Generate your options. Click on “Generate,” and the tool will come up with multiple subject line variations, offering a range of selections for you to consider.

3. Review and refine. AI is a great tool, but AI-generated subject lines shouldn’t be used as-is. Pick the subject lines you like and edit them to get the best result for you.

4. A/B test before you commit. Choose your top two options and test them against your audience to get an accurate view of which option performs better.

Why your subject line makes or breaks your open rate

It's the first — and sometimes only — thing people see.

Nearly half of email recipients (43%) make their open decision based solely on the subject line. Conversely, if subject lines don't perform well, 69% of recipients report the email as spam altogether.

Scale without the bottleneck.

Spending time crafting the right subject line has to make sense. But for busy ecommerce marketers launching campaigns, preparing for seasonal campaigns, and developing automated flows, our AI generator can help get to the subject line that works.

Beat writer's block.

Our AI subject line generator makes it easier to get the first lines faster. Writers and email marketers can use this tool to focus on perfecting, rather than drafting.

Built-in variety for A/B testing.

Get more variations, test, and identify your winning subject lines. Reduce the time you spend on singling out subject lines, and use that valuable time to test different variations.

Tips for getting better results from the generator

1. Be specific with your input. It’s best to be as specific as possible with your prompts to avoid getting generic subject lines.

2. Define your tone. Our generator is fully capable of working with tone cues, so when you enter “urgent”, “playful”, “premium”, or “friendly ”, the AI subject line generator will come back with subject lines using those tones.

3. Mention your audience. Just like tailoring email text to different audience segments, separating subject lines for loyal customers and new subscribers is crucial for improving open rates.

4. Treat the output as a draft, not a final. Tools are great, but they won’t ever change the human touch. Use the subject lines you get and edit them to really match your brand’s voice.

5. Pair with the subject line tester. Once you pick the subject lines you like most, you can run them through Omnisend’s subject line tester to see how our platform scores your subject lines.

We're not just about subject lines

Check out these free tools we designed to help you save time and streamline your work:

Subject line tester

Want a second opinion on your subject lines? Our subject line tester is ready to weigh in and help you fine-tune your copy for maximum impact.

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AI email generator

Use our AI email generator to draft entire email copy in seconds, giving you more time to work on creating the best possible version.

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SMS length calculator

Get the perfect companion tool to help you craft your SMS campaigns. Count characters, estimate costs, and see how your campaign looks on different phones.

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