Email · Free Tool

Cold Email Subject Line Generator

Describe your prospect and offer, and get 10 battle-tested subject line variations — optimised for open rate, not spam filters.

Generate subject lines that get opened

Your subject line is the only thing standing between your email and the trash folder. Studies consistently show that 35% of recipients open emails based on the subject line alone. Yet most reps spend less than 10 seconds writing one.

The anatomy of a winning subject line

The best cold email subject lines share a few traits: they're specific (not "quick question"), they create curiosity without being clickbait, they feel like they came from a human, and they're under 50 characters — short enough to read fully on mobile.

What we generate

Describe your prospect and your offer, and we'll return 10 variations across different angles: personalisation (their company name, recent news), pain-point-led, curiosity-driven, social proof, and direct ask. You pick the one that fits your tone.

A/B test at scale

Inside WaffleIQ, you can A/B test subject lines across your sequences automatically. The platform tracks open rates per variant and surfaces a winner when it reaches statistical significance — so your best subject line gets more sends, automatically.

Avoid spam triggers

Our generator avoids words and patterns that reliably trigger spam filters: excessive punctuation, ALL CAPS, "free", "guaranteed", and overuse of the prospect's first name. You get lines that land in the primary inbox, not promotions.

Ready to scale?

Use Cold Email Subject Line Generator at scale in WaffleIQ

Run bulk lookups, enrich your CRM automatically, and connect results directly to your outbound sequences.

Start for free