Customer.io
Behavior-triggered email, push and in-app messaging for SaaS products
About Customer.io
## Intro Customer.io is a messaging automation platform for sending emails, push notifications, in-app messages, SMS and WhatsApp based on what people do in your product. It is built for SaaS and app companies that want behavior-triggered onboarding and lifecycle messages rather than one-off newsletters. You send it data about your users and what they do, then build journeys that react to that data. A user who signs up but never creates a project can get a nudge on day three, while a power user gets an upgrade offer. It sits closer to your product than a typical email marketing tool. ## Key features - **Journeys.** A visual workflow builder for multi-step, cross-channel campaigns, with send-time optimization, LLM actions and API-triggered broadcasts on every plan. - **Channels.** Email, push and in-app messages, WhatsApp, LINE and webhooks, with SMS priced separately. - **Audiences.** Segments based on behavior and attributes, an AI-powered segment builder, and custom objects for modeling things like accounts or subscriptions. - **Data and AI.** Reverse ETL, a data index and an MCP server on every plan, plus an AI agent in beta for building and running campaigns. ## Best for Customer.io suits SaaS founders and growth teams with product event data who want to send the right message when a user signs up, stalls or upgrades. Apps with mobile users benefit from having push, in-app and email in one place. It is not the right tool for a creator newsletter or simple broadcast emails, where Beehiiv or MailerLite are cheaper and easier. ## Pricing summary Essentials starts at $100 a month with 5,000 profiles and 1M email sends. Extra profiles cost $0.009 each on Essentials. Premium starts at $1,000 a month billed yearly, and Enterprise is custom. A Startup Program offers 12 months free to startups that have raised under $10M. ## Quick verdict Customer.io is a powerful choice for product-led lifecycle messaging, and its data features are strong. The $100 floor is high for a pre-revenue project, and you will need a developer to send product events before it shines. If you qualify, the Startup Program makes it much easier to try. Plan your event tracking before you sign up: decide which user actions matter, such as signed up, created a project or invited a teammate, and send those first. Good data in makes the journeys far more useful, and you can add more events as you learn.
