Beautiful campaigns, blazing-fast transactional emails, drag-and-drop automations, and analytics that actually help you grow.
No credit card • 1,000 free emails/mo
Sent today
48,210
+12% vs last week
Open rate
42.8%
+3.4% vs last week
Click rate
8.1%
+1.1% vs last week
Marketing, transactional, automation — one bill, one API, one truth.
Pixel-perfect emails without writing HTML. Or upload your own.
Sub-second sending with SMTP relay & REST API. Built for scale.
Trigger-based journeys with conditions, delays, and branches.
Opens, clicks, bounces, geo, devices — and exportable reports.
DKIM, SPF, DMARC verification & content scoring out of the box.
Send from your own domain with one-click DNS guides.
From your first newsletter to billions of API sends — Onionstacks grows with you, without the enterprise tax.