Is MailerLite free?

It does have a free tier with most of the features you'd need to get up and going. Advanced automations, and removing Mailerlite branding is available only with paid accounts.

There is a free version that does not have as many features as the paid version. The paid version begins at $10 per month for up to 1,000 subscriber. The $10 is not much and is worth it, depending on how much you use the service.