Email Subject Line Generator

10+ ranked subject lines with open-rate scoring and paired preheaders.

Campaign

0 / 500 characters

10+Per Batch

7Score Axes

30+Languages

FreeNo Signup

What is an email subject line generator?

An email subject line generator turns your email topic into a list of subject lines designed to get opened. The good ones score each line against open-rate signals: clarity, curiosity, length, spam-trigger density, and personalization fit.

This tool returns 10+ ranked lines per batch, scored on 7 axes including a 600-word spam-trigger check, with paired preheader text and cross-client emoji safety. Free for 25 batches per day with no signup. CoSchedule and HubSpot lock equivalent features behind paid plans.

How It Works

Type your topic

Describe what your email is about. Two sentences is enough. Add audience and goal if you have them.

Pick a tone

Curiosity, urgency, benefit-led, casual, or professional. Same topic, very different open rates.

Get 10+ ranked lines

Each subject line scored on 7 axes including spam-trigger words. Top 3 get a green star.

Every feature, one tool

Open-rate prediction

Each line scored on 7 axes: clarity, curiosity gap, length, urgency, personalization, spam triggers, and emoji density. Calibrated against the AWeber industry benchmark.

Spam-filter check

We test every line against 600+ known spam-trigger words. Lines that score above 60% in any one trigger get auto-rewritten and dropped.

Preheader pairing

Each subject line comes with a matching preheader (the gray text after the subject). Together they form the full inbox preview, scored as one unit.

Cross-client emoji safe

We test which emoji actually render across iOS, Android, Outlook, and Gmail. Only the cross-client safe ones get suggested.

30+ languages

Type your topic in any language; the lines come back in that language. Length tuning still respects the inbox preview cap of each language.

Campaign-aware

Pick the campaign type (cold sales, newsletter, transactional, abandoned cart, re-engagement, product launch). The prompt adjusts to each context.

Brand voice (Pro)

Save your tone, banned words, and signature phrases. Every batch then writes in your voice.

Privacy-first

We do not store the topics you generate from. Sessions expire on browser close. Pro offers encrypted history.

Why this generator

25 batches per day, free

CoSchedule limits non-paid use to one line score. We give you 250+ ranked subject lines every day. Most marketers ship 1-2 emails per week. This is plenty.

Side-by-side comparison

All 10+ lines render in a sortable list with score, length, spam risk, and predicted open rate. Sort by any column. Pick 3 for an A/B test.

Honest scoring

Bad ideas get a red badge. We do not pretend every line is great. The scoring algorithm is open about what it weighs and why.

No data retention

We do not log topics or generated lines. Run 100 brainstorms a day and nothing accumulates. Privacy first by default.

Who uses it

Sales reps

Cold outreach lines that get past spam filters and into the inbox. Personalization slots auto-marked so you can swap in {firstName}, {company}, {painPoint}.

Newsletter editors

Punchy lines that lift open rates 2-3 points week over week. Run 5 styles, A/B the top 2, learn what your list responds to.

Ecommerce founders

Abandoned cart, win-back, post-purchase, and product launch templates. Each campaign type has its own line patterns that convert.

Community builders

Casual lines that feel like a friend, not a marketer. Curiosity tone is the highest-converting style for community newsletters.

Real moments you would use it

You sent a great email last week and the open rate was a depressing 14%. The body was strong but the subject line was generic.
You are launching a new feature on Tuesday and the subject line decides whether 50K subscribers click. You need 10 options to A/B test.
Your CEO sent you a draft that says 'Hello!' as the subject. You need to rewrite it without sounding like you are correcting them.
You are running a cold outreach campaign and 80% of your emails land in promotions tab. You need lines that read more personal.
You are sending a re-engagement campaign to a list that has not opened in 90 days. Standard lines will not move the needle.
You are pitching the same product to 5 personas and need a different angle for each so the same offer feels relevant to each segment.

Versus the others

Feature	Molixa	CoSchedule	HubSpot	Mizy
Free daily limit	250+ lines (25 batches × 10)	1 line score/day	Limited free	5 free posts/day
Open-rate scoring	7 axes, calibrated	Yes	Basic	No
Spam-trigger check	600+ words checked	Limited	No	No
Preheader pairing	Yes	No	No	No
Multi-language	30+ languages	English only	English only	Limited
Campaign types	6 (cold, newsletter, etc.)	Generic	Generic	Newsletter only
Cross-client emoji	iOS/Android/Outlook/Gmail	No	No	No
Brand voice profile	Pro	No	Workflow add-on	No
Privacy	No retention	Stored	Stored in CRM	Stored

Frequently Asked Questions

Is the email subject line generator free?▾

Yes. 25 free batches per day with no signup. Each batch returns 10+ subject lines ranked by predicted open rate. CoSchedule limits non-paid use to a single line score. We give you 10 fresh ideas.

How does the open rate prediction work?▾

We score each line on 7 axes: clarity, curiosity gap, length (mobile preview cap is 41 chars), urgency, personalization, spam-trigger words, and emoji density. The composite score is calibrated against the AWeber industry benchmark dataset.

Can I pick a tone or style?▾

Yes. Curiosity, urgency, benefit-led, casual, and professional. The same email topic produces very different subject lines across styles. Run two passes if you want to A/B test tones in your sending tool.

Will the subject lines avoid spam filters?▾

We check each line against a list of 600+ known spam-trigger words (FREE!!!, ACT NOW, double exclamation marks, all caps). Lines that score above 60% in any one trigger get auto-rewritten and dropped from the batch.

Can I generate subject lines in other languages?▾

Yes. Type your topic in any language and the lines come back in that language. Spanish, German, French, Hindi, Arabic, Mandarin, plus 25+ others. Length tuning still respects the inbox preview cap of each language.

Does it work for cold outreach vs. newsletters?▾

Yes. Pick the campaign type (cold sales, newsletter, transactional, abandoned cart, re-engagement, product launch) and the prompt adjusts. Cold outreach lines stay under 50 chars. Newsletter lines can be punchier and longer.

Can I get preheader text too?▾

Yes. Each subject line comes with a matching preheader (the gray text after the subject in inbox previews). Preheader and subject together are scored as one unit because that is how readers actually see them.

What about emoji in subject lines?▾

Optional. Toggle on for B2C and casual, off for B2B and finance. We test which emoji actually render across iOS, Android, Outlook, and Gmail and only suggest the cross-client safe ones.

Will it remember my brand voice?▾

Pro saves your brand voice profile (tone, banned words, signature phrases). Every batch then writes in your voice. The free tier is one-shot.

Is my email data private?▾

Yes. We do not store the topics you generate from. Sessions expire on browser close. Pro accounts can opt in to cloud history with end-to-end encryption.

Stop guessing at subject lines

Free for 25 batches per day. 10+ ranked lines per batch. No signup. No card.

Generate subject lines now

Built and reviewed bySaqib Zahoor, WeboTech Studio

Last updated: May 14, 2026

The Email Subject Line Generator page is built, reviewed, and maintained by the Molixa team. We use the tool we ship and update the docs when the behavior changes.

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