Test and generate email subject lines
with AI

Increase your open rates in real-time.

Get Started FreeContact Sales
Screenshot of Envelope App
Superlines UI

Your virtual email growth hacker

Superlines pretests email subject lines for you in seconds using our benchmark data and machine learning. It also automatically writes more subject ideas and tests how good they are.

Subject tester

Save hours of work weekly with instant open rate predictions.

Automated copywriting

Let Superlines automatically write new subject line ideas.

For strategists

Use Superlines to predict results already when planning your marketing campaigns.

For content creators

No more hours of work spent on A/B testing and thinking about new subject variations.

Better marketing with AI powered copywriting and content testing.

Screenshot of Envelope App

Train Superlines with your data

Import subject line and open rate data from your email platform to Superlines, and it will learn what type of subject lines your users like the best.

Works with Adobe Campaign, SalesForce Marketing Cloud, Mailchimp and more.

Contact sales
state of the art speaker

Estimate your annual added revenue

This calculation is based on our experience on a 5% increase in open rate from AI-powered optimization. In reality, it may be even higher, and the calculation does not take into account the cost savings achieved by automatic content creation and copywriting, which further increases the MROI.

Revenue increase in one year 121500

Want a custom one?

Contact our sales team to train Superlines with your own email data or data from other marketing channels such as Google Ads, Twitter Ads, and more.

Built by AI & marketing tech entrepreneurs

We have over a decade-long experience of how time-consuming writing content, A/B testing, and optimization work can be.

We created Superlines to help other marketers, entrepreneurs, and companies increase marketing results while making sure they can focus on things that matter the most.

Using Superlines, you have the power to use advanced AI that will save you hours of work weekly and increase your chances of reaching your targets.

- Superlines team



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Soon available as multichannel with direct integrations!

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