transactional messages

Build long-lasting relationships

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Trusted by 8,000+ brands

transactional messages

Build long-lasting relationships

Form not working? Click here to get your referral link

Trusted by 8,000+ brands

transactional messages

Build long-lasting relationships

Form not working?
Click here to get your referral link

Trusted by 8,000+ brands

We unify your data, messaging, and AI into a single platform, so every interaction with your customers is stronger and more relevant than the last.

Send critical messages instantly

Engage across the entire journey

Deliver receipts, password resets, and alerts the moment users need them.

Surface high-intent segments and automatically uncover behavioral patterns in your first-party data.

Trigger programmatically via API

Smarter journeys.

Send messages directly from your backend with full control over content and timing.

Build and optimize cross-channel workflows from a conversation, with logic the Agent configures for you.

Reach users across key channels

Stronger content.

Deliver transactional messages via email, SMS, and push—wherever your users are.

Draft, refine, and iterate on messaging while the Agent maintains your brand voice and guardrails.

Reliable Messaging

Deliver critical messages—instantly and at scale

Reliable Messaging

Deliver critical messages—instantly and at scale

Reliable Messaging

Deliver critical messages—instantly and at scale

Send

Trigger messages the moment they’re needed

Respond to user actions like purchases, logins, or requests with immediate, expected messages—no delays or workflows required.

Send

Trigger messages the moment they’re needed

Respond to user actions like purchases, logins, or requests with immediate, expected messages—no delays or workflows required.

Control

Build and send with full API flexibility

Use the transactional API to send messages programmatically, pass dynamic data, and control every aspect of delivery.

Control

Build and send with full API flexibility

Use the transactional API to send messages programmatically, pass dynamic data, and control every aspect of delivery.

Deliver

Ensure high deliverability for critical messages

Send through infrastructure designed for transactional use cases, helping important messages reach inboxes and devices reliably.

Deliver

Ensure high deliverability for critical messages

Send through infrastructure designed for transactional use cases, helping important messages reach inboxes and devices reliably.

Customers love us

Preferred by product-led companies

Mailchimp was so difficult to integrate and required so much manual work. The implementation was so easy with Customer.io, the automatic setup and integration. With a click of a button, we were able to immediately start sending campaigns to our users. Plus they didn’t have the workflows Customer.io does.

Ben Spring

Co-Founder

At the end of the day, we’re trying to deliver exactly what the customer wants. By using event conversions and segments, we’re giving them what they need and what they expect to get.

Matt Hayes

Email Marketing Manager

Using Customer.io has boosted our numbers in every imaginable way—from audience growth to engagement to conversion. They are literally helping us change lives around with world.

Grace Garey

Co-Founder