Top Klaviyo alternatives in 2026 (pros, cons, pricing)

Klaviyo, a marketing platform popular for ecommerce email and SMS campaigns, is often outgrown by teams needing more control, API flexibility, and cross-functional collaboration. While Klaviyo excels in traditional marketing scenarios, it falls short in transactional messaging, cross-channel orchestration, and pricing models, prompting organizations to explore alternatives. Various platforms offer solutions to these limitations: Knock provides comprehensive cross-channel customer engagement infrastructure, enabling collaboration across engineering, product, growth, and operations teams with API-first infrastructure and visual tools. Customer.io caters to product-led SaaS companies needing behavior-driven messaging, while Braze and Iterable serve enterprise marketing teams with real-time and AI-powered campaign orchestration, respectively. OneSignal offers a cost-effective push notification service, Novu provides open-source notification infrastructure, and Courier offers a unified API for developers managing multi-channel notifications. Each alternative addresses specific needs, such as transactional messaging, cross-functional collaboration, and budget constraints, offering more channels and flexibility than Klaviyo's marketing-centric model.