Beanoc.
Start $1 trial
Email Marketing

AI email subject line generator with preview text included

Subject line and preview text are one unit — most tools write only the first. This AI writing assistant produces fifteen pairs, checked against mobile truncation, across curiosity, benefit, urgency and plain-spoken styles.

Start for $1 See pricing

What the subject line lab gives you

  • Fifteen subject lines with the preview text written to complete, not repeat, each one.
  • Length guidance for mobile clients that cut around 35 to 40 characters.
  • A clickbait check, so the subject never promises something the email does not deliver.

Who it is for

Email marketers, newsletter writers, ecommerce teams and anyone A/B testing sends weekly.

Why it is different

Pairs, not lines. Optimising the subject alone leaves the second most-read text in the inbox to chance.

Example: Subject lines for a restock announcement

An illustrative brief and output written by our team to show the format. It is not a customer result and makes no performance claim.

The brief

Email
Best-selling wool blanket back in stock in three colours
List
Past customers and waitlist

The output

Subject lines with preview text

  • Plain: The wool blanket is back — Three colours, and the grey usually goes first.
  • Specificity: Back in stock: 240 blankets — Restocked this morning, waitlist first.
  • Curiosity: You asked us to email you — So here it is, the blanket is back.
  • Low-key: It's back — No countdown, no drama. Just the restock you wanted.

How it works

  1. 01

    Fill the brief

    Guided fields ask for product, audience and outcome — no prompt writing.

  2. 02

    Generate

    The AI email subject line generator runs server-side with your saved brand voice applied.

  3. 03

    Ship it

    Copy the structured output, or find it again in your searchable history.

Subject Line Lab FAQs

How long should an email subject line be?+

Aim for around 40 characters so it survives mobile truncation. Longer works when the first 40 characters already carry the meaning.

Do emojis improve open rates?+

Results are audience-dependent and the effect is small. The tool can include them on request but never adds them by default.

Can I test these as A/B variants?+

Yes — the fifteen lines are deliberately spread across styles so a test compares approaches rather than synonyms.

Related email tools

Or browse all email marketing tools, or the full library of 45 AI marketing tools.

Use the Subject Line Lab today for $1

Seven days of full access to all 45 tools, then $19/month. Cancel in one click.

Start your $1 trial