Free Email Subject Line Tester

Type a subject line to test it. The analyzer scores length, spam triggers, personalization, and emoji use, then shows how it looks in the inbox.

0 characters 0 words

Score

0 -

Length

Enter a subject line

Emojis

No emojis detected

Personalization

No personalization detected

Inbox Preview

Mobile (iPhone)

B

Your Brand

Your subject line...

Preview text appears here and continues...

9:41 AM

Desktop (Gmail)

Your Brand Your subject line appears here 9:41 AM

Issues Detected

Enter a subject line to check for issues

Suggestions

  • Enter a subject line to get suggestions

Subject Line Best Practices

Optimal Length

  • 30-50 characters is ideal
  • Mobile shows ~35 characters
  • Desktop shows ~60 characters
  • Shorter often performs better

Avoid Spam Triggers

  • Words like "FREE", "URGENT", "Act Now"
  • ALL CAPS text
  • Excessive punctuation (!!!)
  • Misleading claims

Personalization

  • Use recipient's name when possible
  • Can increase open rates by 20%+
  • Keep it natural, not forced
  • Test with and without
✨

Emojis

  • 1 emoji can increase open rates
  • Use sparingly (1-2 max)
  • Place at start or end
  • Test emoji vs. no emoji

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