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Email subject line and preview text checker

Paste a subject line and preview text to see how an inbox shows them and get instant checks on length, capitals, punctuation and misleading prefixes; it runs in your browser and needs no email address.

By Tellnod team · Updated

Phone inbox
Your shopThe autumn lot is roasted, Ava15% off for regulars until Oct 25. Two new single origins just came out of the roaster.
  • Fix: 41 characters: phones may cut it after about 40. Put the key words first.
  • Note: Uses a merge tag. Make sure every contact has a value, or set a fallback.
  • Good: Preview text is 87 characters.

What it checks

  • Length against what phones and desktop inboxes usually show
  • Mostly capital letters and repeated punctuation
  • Misleading "Re:" or "Fwd:" prefixes (CAN-SPAM bans deceptive subjects) S2
  • Merge tags that need a fallback
  • Missing, short, long or repeated preview text

Tellnod runs these checks on every campaign before the confirmation card, and adds the unsubscribe link, headers and postal address for you.

FAQ

How long should an email subject line be?

Short enough that the key words show on a phone: phones often cut after about 40 characters, so put the important words first and keep it under about 60.

What is preview text?

The line an inbox shows next to or under the subject. If you leave it empty, the inbox shows the opening words of the email. See preheader.

Do you store what I type?

No. The checker runs entirely in your browser; nothing is sent to us.

Sources

  1. [S2] FTC: CAN-SPAM Act compliance guide for business, checked