Which is cheaper, Customer.io or Resend?

Resend is 5.0x cheaper than Customer.io. Customer.io starts at $100/mo, Resend starts at $0/mo.

Does Customer.io have a free tier?

No, Customer.io does not have a free tier.

Customer.io has significant switching cost. Resend has drop-in switching cost. Resend is easier to switch away from.

Customer.io

Automated messaging platform for targeted emails, push notifications, SMS, and in-app messages based on user behavior

Switching Cost: significant

Resend

← More affordable

Developer-first email API for transactional and marketing emails

Switching Cost: drop-in

You're paying a premium for Customer.io — expect around a 5.0x higher bill compared to Resend.

The free tier advantage goes to Resend, which offers a no-cost entry point that Customer.io lacks.

If budget is your primary constraint, Resend is the clear winner with its more wallet-friendly pricing structure.

If budget is your primary constraint, Resend is the clear winner with its more wallet-friendly pricing structure.

Price Difference

5.0x

Resend is cheaper by $80/mo

Free Tier

Resend

Has a free tier option

Switching Costs

Resend

Lower switching costs for easier migration