Free Cold Email Subject Line Checker

Check your subject line for length, spam-trigger words, and formatting red flags before you hit send. Free, no sign-up, instant results.

Your subject line

Result

Type a subject line above

✓ 100% free✓ 60+ spam trigger words✓ No sign-up

How it works

Three steps, no fuss.

Paste a subject line

Try the one you're about to send.

Get an instant score

We check length, spam words, and formatting red flags.

Fix and resend

Tweak flagged words and aim for a higher score before you hit send.

FAQ

Subject line questions, answered.

What does the score mean?

It's a quick heuristic score out of 100 based on length, spam-trigger words, and formatting patterns (like ALL CAPS or multiple exclamation marks) that commonly hurt deliverability. It's a guide, not a guarantee.

Does this check spam filters directly?

No. It flags patterns known to increase spam-complaint risk, based on common cold-email best practice. Actual deliverability also depends on your sending domain, volume, and reputation.

Is my subject line stored anywhere?

No, everything runs in your browser and is never sent to a server.

Is this tool free?

Yes, completely free with unlimited use.

Need a tool built just for you?

This free tool is a small taste of what we do. Go4Lead.tech builds custom software, web and mobile apps, and internal tools for businesses.

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