📧 Email Tools

Subject Line Previewer

See exactly how your subject line looks in every major email client — with live truncation, character counts, and inbox previews.

Sender name 0 / 25

Reply-to / From address (optional)

Subject line 0 chars

Preheader text (preview text shown after subject) 0 / 90

Gmail — Desktop

Your Name 10:32 AM

Subject chars 0 / 77

Gmail — Mobile

Your Name 10:32

Subject chars 0 / 40

Outlook — Desktop

Your Name Tue 10:32 AM

Subject chars 0 / 73

iPhone Mail 9:41 AM

Your Name

10:32 AM

Subject chars 0 / 35

Apple Mail — macOS

Your Name

—

Tuesday

10:32 AM

Subject chars 0 / 60

Character limits by client

Gmail Desktop

chars

Gmail Mobile

chars

Outlook

chars

Apple Mail

chars

iPhone Mail

chars

How to use this tool

1 Type or paste your email subject line into the input field.

2 The tool shows a live preview of how it appears on desktop and mobile inbox views.

3 Adjust the subject until the key message is visible without truncation.

4 Use the character count guide to stay within the recommended 60-character limit.

Frequently asked questions

How many characters should an email subject be?

Keep it under 60 characters so it does not get cut off on mobile. The most important information should appear in the first 40 characters.

Does capitalization affect open rates?

Yes. Title case and sentence case tend to perform better than all caps, which can trigger spam filters and feel aggressive.

Should I use emojis in subject lines?

Emojis can increase open rates when used sparingly and when they match the tone of the email. Avoid them in formal business communications.

What makes a subject line effective?

Clarity, relevance, and a specific hook. Vague lines like 'Update' or 'Important info' perform worse than specific ones that tell the reader exactly what is inside.