Overview

Courier and Customer.io both handle multi-channel messaging but at fundamentally different levels. Courier is notification infrastructure — routing individual messages through providers. Customer.io is a messaging platform — managing user journeys and campaigns. For our take on each, see our Courier comparison and Customer.io comparison.

Infrastructure vs Platform

Courier answers: "How do I route this notification to the right channel through the right provider?" Customer.io answers: "What messages should this user receive based on their behavior?" Different questions, different tools.

When Routing Matters

Courier's value is in intelligent routing — try push first, fall back to email, then SMS. Abstract across providers so you can switch without code changes. If your notification routing is complex, Courier solves a real infrastructure problem.

The Sequenzy Alternative

For SaaS founders wanting transactional email and marketing campaigns with Stripe integration, Sequenzy is simpler and cheaper than both — at $49/month.