AI Email Subject Line Generator

An AI email subject line generator writes the line that decides whether an email gets opened. You choose the email type (promotion or sale, newsletter, welcome email, abandoned cart, re-engagement, product launch or event invite), pick a tone of Professional, Friendly, Urgent or Curious, and say what the email is about. A language model returns 15 subject lines and then suggests preview text for the best five.

Fifteen is the point. The first idea is rarely the best, and testing needs options. The prompt mixes styles on purpose: questions, numbers, urgency, personal lines, curiosity, and one or two with an emoji. Each is kept under 50 characters, because phone inboxes cut long subjects short. The preview text is the grey line after the subject in most inboxes, and a subject and preview written as a pair get more from the space than a subject alone.

It avoids obvious spam-trigger phrasing such as "free money" and all caps. That is not a deliverability guarantee: whether mail lands in the inbox depends mostly on your sender reputation, authentication (SPF, DKIM and DMARC) and how recipients engage, none of which a subject line fixes. The model also has no data on your list, so it cannot predict open rates. Run an A/B test in your email platform to find out which line works.

The model runs on the Toolz server. Your form is sent over HTTPS, the server builds the prompt and runs Gemma 3 1B, a small open model from Google, with Ollama, and the lines stream back as they are written. Campaign details and unreleased offers are used to write the reply and then discarded: they are not stored or logged, not used to train any model, and not sent to any third-party AI company. A 1B model miscounts characters and may go over 50 or repeat an idea, so check the length and trim as needed.

It is free with no signup, within about 20 runs per 10 minutes. You could brainstorm alone, reuse last year's winners, or use the built-in assistant in a paid email platform. For a sales email to one prospect, the AI Cold Email Generator writes the whole message.