Email Subject Line Tester — free online
You write an email, you spend ages on it, and then the subject line is the first thing people see. If it's too long, sounds spammy, or shouts in capital letters, it can land in the wrong folder or just get ignored. We added a free tool that checks it for you — Email Subject Line Tester — right in your browser.
What it does
Type a subject line and get an instant score. It looks at the length, flags spam-trigger words, points out emoji and ALL-CAPS, and shows you an inbox preview so you can see how it'll really look. You catch the small problems before you hit send.
Nothing leaves your device
The whole thing runs in your browser. Your subject line isn't uploaded anywhere and nothing is saved. When you close the tab, it's gone — only you ever see what you typed.
How to use it
- Open Email Subject Line Tester and type your subject line in the box.
- Read the score and the notes about length, spam words, emoji and caps.
- Tweak the wording until it looks good, then use it in your email.
It's free with no limit. There are more small tools on the Apps page.