Subject line tester

Check a cold email subject line before you send.

Test for readable length, clear intent, useful personalization, real urgency, and common spam-trigger phrases.

Keep it clear

One subject line, one quick risk review.

The tester gives a practical quality signal before you move to the full email and deliverability checks.

6

checks

250ms

local review

0

delivery guarantees

Test your subject line

Paste one subject line. Keep the analysis simple and revise until the subject line sets a clear expectation.

What the tester checks

A good cold email subject line should be easy to scan, specific to the message, honest about urgency, and free of obvious spam-trigger phrases.

Length and mobile readability

Specificity and recipient context

Urgency and spam-trigger risk

Match the email body

The subject line should promise exactly what the message delivers.

Avoid fake urgency

Deadlines and limited-time language should only appear when true.

Check the full message

The subject line is one signal. The email body still needs a spam and deliverability review.

Next step

Turn the subject into a clearer cold email.

Use the generator for the message, then run the full copy through the spam score checker before sending.

Generate email

What does the score mean?

It is a practical quality check, not a delivery guarantee. Use it to spot length, clarity, personalization, urgency, and spam-trigger issues.

Should every subject line use urgency?

No. Urgency only helps when it is true. Fake urgency can hurt trust and can look like a spam signal.

What should I do after this?

Run the full message through the spam checker, then generate or revise the email with the same clear offer and audience.

Subject Line Tester | Check Clarity and Spam Risk | Folderly