Organization and Business Description	3 Months Ended
Mar. 31, 2025
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Business Description	1. Organization and Business Description Klaviyo, Inc. (the “Company”) is a technology company that provides a modern, vertically integrated software-as-a-service (“SaaS”) platform to enable consumer-focused businesses to capture, store, analyze, and predictively use their own data to drive measurable, high-value outcomes. Klaviyo's platform combines proprietary data and application layers into one solution with machine learning, artificial intelligence capabilities, and integrations. The Klaviyo Data Platform (“KDP”) is the foundation of the platform unifying customer data for a single view of the customer and enabling real-time activation of data across a range of applications. The Company focused on marketing automation within eCommerce with Klaviyo Marketing as its first application use case and has since expanded its suite of applications to include customer Klaviyo Service, Klaviyo Analytics, and advanced data management through its Advanced KDP. The Company’s marketing automation solution allows customers to orchestrate campaigns across multiple marketing channels including email, short message service (“SMS”) and Mobile Push and collect product reviews within its platform through the Company’s Reviews add-on. The Company generates revenue through the sale of subscriptions to its customers for the use of its platform. Subscription plans are tiered based on the number of consumer profiles stored on the Company’s platform and the number of emails and SMS messages sent. 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”) is a technology company that provides a modern, vertically integrated software-as-a-service (“SaaS”) platform to enable consumer-focused businesses to capture, store, analyze, and predictively use their own data to drive measurable, high-value outcomes. Klaviyo's platform combines proprietary data and application layers into one solution with machine learning, artificial intelligence capabilities, and integrations. The Klaviyo Data Platform (“KDP”) is the foundation of the platform unifying customer data for a single view of the customer and enabling real-time activation of data across a range of applications. The Company focused on marketing automation within eCommerce with Klaviyo Marketing as its first application use case and has since expanded its suite of applications to include customer Klaviyo Service, Klaviyo Analytics, and advanced data management through its Advanced KDP. The Company’s marketing automation solution allows customers to orchestrate campaigns across multiple marketing channels including email, short message service (“SMS”) and Mobile Push and collect product reviews within its platform through the Company’s Reviews add-on.

The Company generates revenue through the sale of subscriptions to its customers for the use of its platform. Subscription plans are tiered based on the number of consumer profiles stored on the Company’s platform and the number of emails and SMS messages sent.