Klaviyo is a B2C CRM, a customer relationship management system for companies that sell to consumers, with email and text-message marketing at its core. It is made by Klaviyo, Inc.
The Klaviyo Data Platform collects customer profiles, events (such as a viewed product or a placed order) and properties into one view per customer, fed by more than 400 pre-built integrations with other tools, such as Shopify. On this data a marketer builds segments (groups of customers selected by rules), sends campaigns (one-time messages) and sets up flows, automated sequences that start when an event happens, such as a placed order. Messages go out by email, SMS and RCS text, WhatsApp, mobile push and web forms. Other products add reviews, a helpdesk, an AI customer-service agent and Composer, an AI marketing agent. Developers reach the same data through public APIs and an MCP server.
It is a hosted service with a free plan. Paid plans are subscriptions priced by active profiles, the contacts who can receive marketing; unsubscribed and suppressed contacts do not count.