Organization and Business Description	3 Months Ended
Mar. 31, 2026
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Business Description	1. Organization and Business Description Klaviyo, Inc. (the “Company” or “Klaviyo”) is a technology company that provides a cloud-based, software-as-a-service (“SaaS”) platform that enables consumer-focused businesses to capture, store, analyze, and use their first-party data to create and deliver personalized consumer experiences across digital channels. The Company’s platform combines proprietary data, action, and intelligence layers to unify customer data and support real-time activation across multiple use cases, including marketing, customer service, analytics, and data management. The Company’s platform includes marketing automation capabilities that allow customers to orchestrate campaigns across multiple channels, including email, text messaging, WhatsApp messaging, and mobile push. The Company also offers customer service solutions, including Customer Agent, Customer Hub and Helpdesk, as well as marketing analytics, and data platform functionality. The Company generates revenue through the sale of subscriptions that provide customers access to its platform. Subscription plans are tiered based on the number of consumer profiles stored on the Company’s platform and the number of emails, text messages, and WhatsApp messages sent as well as customer tickets and conversations through Klaviyo Service. The Company is headquartered in Boston, Massachusetts and was incorporated in the state of Delaware on September 14, 2012. The Company has several wholly-owned subsidiaries in the United States and international jurisdictions.

Klaviyo, Inc. (the “Company” or “Klaviyo”) is a technology company that provides a cloud-based, software-as-a-service (“SaaS”) platform that enables consumer-focused businesses to capture, store, analyze, and use their first-party data to create and deliver personalized consumer experiences across digital channels. The Company’s platform combines proprietary data, action, and intelligence layers to unify customer data and support real-time activation across multiple use cases, including marketing, customer service, analytics, and data management.

The Company’s platform includes marketing automation capabilities that allow customers to orchestrate campaigns across multiple channels, including email, text messaging, WhatsApp messaging, and mobile push. The Company also offers customer service solutions, including Customer Agent, Customer Hub and Helpdesk, as well as marketing analytics, and data platform functionality.

The Company generates revenue through the sale of subscriptions that provide customers access to its platform. Subscription plans are tiered based on the number of consumer profiles stored on the Company’s platform and the number of emails, text messages, and WhatsApp messages sent as well as customer tickets and conversations through Klaviyo Service.

The Company is headquartered in Boston, Massachusetts and was incorporated in the state of Delaware on September 14, 2012. The Company has several wholly-owned subsidiaries in the United States and international jurisdictions.