Email Subject Line Tester
Checks how a subject line will appear across inboxes, where the available space is much shorter than most people assume. Mobile clients commonly show only 35-45 characters, so anything important needs to come first.
Free, no signupRuns entirely in your browser
Input
Result
- Selected Topic Campaign
- SALES
- Email Subject Line Templates
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About
What the Email Subject Line Tester does
Front-loading is the whole technique. A subject line that builds to its point loses the point entirely when truncated, whereas one that leads with the substance still works even when cut. The preheader text — the snippet shown after the subject — is worth writing deliberately too, since most senders leave it as whatever the email starts with.
How it works
Using the Email Subject Line Tester
- 1Enter your subject line.
- 2The character count is shown.
- 3Approximate truncation points for desktop and mobile are indicated.
- 4Check the important words fall before the cut.
- 5Adjust and copy the final version.
Use cases
What people use it for
- Writing a campaign subject line
- Checking a transactional email subject
- Comparing variants for an A/B test
- Making sure a key detail survives truncation
FAQ
Frequently asked questions
6 related
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