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Free Email Marketing Tool
Score your subject line before you hit send. Check length, spam trigger words, capitalization and emoji use, then see exactly how it truncates in Gmail on desktop and mobile.
Free forever · No account needed · Nothing is stored or sent to a server
A silent SPF or DKIM change can quietly send your emails to spam for weeks before anyone notices. Drop your email and we'll alert you the moment something looks off, so you fix it in minutes, not after a deliverability cliff.
Check every aspect of your email infrastructure
Mailsoftly handles SPF, DKIM & DMARC automatically. Campaigns, automation, and analytics in one place.
Free to start with your Google Workspace account. No credit card required.
This free email subject line tester scores your subject line from 0 to 100 before you send. It checks the length against the 30 to 50 character sweet spot, scans for more than 60 spam trigger phrases, and flags all caps words, repeated punctuation, excessive emoji and missing personalization. It also shows exactly where Gmail truncates your line, at roughly 60 characters on desktop and 35 on mobile, so your key words survive the cut. Everything runs in your browser and nothing is stored.
Aim for 30 to 50 characters and roughly 3 to 9 words. Gmail shows about 60 characters of a subject line on desktop and about 35 on a phone, so anything longer gets cut off for most readers. Put the most important words first so they survive truncation, and pair the subject with preview text instead of cramming everything into one line. Test your line above to see both truncation points instantly.
