Free tool
Will your subject line get opened — or filtered?
The subject line decides your open rate, and a few wrong words can tip you into the spam folder. Paste yours and see a live score with the exact things to fix — plus how it truncates on mobile and desktop.
Type a subject line to score it.
A guide, not a guarantee — inbox placement also depends on your domain reputation, authentication (SPF/DKIM/DMARC) and engagement. This tool never sends or stores anything.
Go deeper on deliverability
Great subject lines, written for you by AI.
- No credit card
- EU data residency
- 6 channels, one API
- GDPR built in
One platform. Every customer interaction.
Replace your patchwork of messaging APIs, CDP and automation tools with a single engagement platform built for scale.
No credit card required · EU data residency · 99.99% uptime SLA