7 Best Alternatives to Klaviyo API in 2026

Why look beyond Klaviyo API

Klaviyo provides an API for integrating its email and SMS marketing capabilities, customer data platform (CDP) functionalities, and marketing automation workflows with other business systems [source]. While Klaviyo is widely used, particularly by e-commerce businesses, developers may seek alternatives for several reasons. These can include specific feature requirements not met by Klaviyo's API, such as highly customized multi-channel orchestration or niche industry compliance standards. Developers might also evaluate alternatives based on pricing structures that better align with their operational budget, especially as contact or send volumes scale. Furthermore, the need for broader SDK support, different authentication mechanisms, or a more extensive ecosystem of pre-built integrations could lead teams to explore other platforms. Performance considerations, such as message delivery speed or API rate limits for high-volume use cases, are also factors. Finally, some organizations may prefer a vendor that offers a more unified platform experience across various communication channels beyond email and SMS.

Top alternatives ranked

1. 1. Braze — Customer engagement platform for cross-channel experiences

   Braze is a comprehensive customer engagement platform designed to help brands build and manage personalized customer experiences across multiple channels, including email, SMS, push notifications, and in-app messages [source]. Its API is built for real-time data ingestion and message orchestration, allowing developers to integrate customer data, trigger campaigns, and manage user segments programmatically. Braze focuses on providing a flexible platform for complex customer journeys, supporting advanced segmentation, A/B testing, and AI-driven personalization. It is often chosen by larger enterprises and fast-growing companies that require sophisticated multi-channel marketing capabilities and robust analytics to understand customer behavior across various touchpoints.

   Best for: Enterprise-grade multi-channel marketing, real-time customer engagement, complex customer journey orchestration, and brands requiring extensive personalization capabilities.

   Explore the Braze API profile.

2. 2. Iterable — Growth marketing platform for unified customer experiences

   Iterable is a growth marketing platform that enables businesses to create and deliver personalized user experiences across email, push, SMS, in-app, and more [source]. Its API is designed for flexibility, allowing developers to integrate data from various sources, build custom workflows, and trigger messages based on user behavior in real-time. Iterable emphasizes its workflow studio, which enables marketers to design intricate customer journeys with branching logic and dynamic content. The platform is known for its robust segmentation capabilities, A/B testing, and machine learning-powered optimization tools. Companies often select Iterable when they need to manage highly individualized customer interactions and scale their marketing efforts across a diverse set of communication channels.

   Best for: Advanced segmentation, highly personalized multi-channel campaigns, real-time data integration, and businesses focused on optimizing customer lifecycle management.

   Explore the Iterable API profile.

3. 3. Mailchimp — Email marketing and automation for small businesses

   Mailchimp is a widely recognized marketing platform primarily known for its email marketing services, offering tools for creating campaigns, managing audiences, and automating workflows [source]. The Mailchimp API provides developers with the ability to programmatically manage contacts, send emails, retrieve campaign reports, and integrate with e-commerce platforms. It is particularly popular among small to medium-sized businesses due to its user-friendly interface and comprehensive feature set for basic to intermediate marketing needs. Mailchimp also offers website building tools, landing pages, and social media management features, making it a more holistic solution for businesses looking for an all-in-one marketing assistant. Its API is well-documented and supports various SDKs, making it accessible for developers.

   Best for: Small businesses, email newsletters, basic marketing automation, audience management, and straightforward e-commerce integrations.

   Explore the Mailchimp API profile.

4. 4. Twilio — Programmable communication for voice, SMS, and video

   Twilio provides a suite of APIs for integrating voice, SMS, video, and other communication functionalities directly into applications [source]. While not a direct marketing automation platform like Klaviyo, Twilio's messaging API (Twilio Programmable Messaging) can be used to build custom SMS marketing and notification systems. Developers leverage Twilio to send transactional SMS, marketing messages, and build interactive communication flows. Its strength lies in its global reach, reliability, and granular control over communication channels. Businesses that require highly customized messaging solutions, two-factor authentication, or complex contact center integrations often choose Twilio to build their communication infrastructure from the ground up, rather than relying on a pre-packaged marketing platform.

   Best for: Custom SMS marketing solutions, transactional notifications, two-factor authentication (2FA), and building scalable, programmatic communication infrastructure.

   Explore the Twilio API profile.

5. 5. Firebase — Mobile and web app development platform with messaging

   Google's Firebase is a platform for developing mobile and web applications, offering a range of services including databases, authentication, hosting, and cloud messaging [source]. Firebase Cloud Messaging (FCM) allows developers to send notification messages and data messages to users across platforms (Android, iOS, web). While primarily focused on app development and user engagement through notifications, FCM can be integrated into broader marketing strategies for targeted messaging. It provides a reliable and scalable way to deliver messages to app users, often used for re-engagement campaigns, product updates, and personalized alerts. Firebase is particularly attractive for developers building applications within the Google ecosystem, offering seamless integration with other Google Cloud services.

   Best for: Mobile and web app developers, sending targeted push notifications, user re-engagement campaigns, and integrating messaging within the Google ecosystem.

   Explore the Firebase API profile.

6. 6. Shopify API — E-commerce platform with extensive integration capabilities

   Shopify provides a comprehensive set of APIs for building and extending e-commerce stores, managing products, orders, customers, and more [source]. While not a marketing platform itself, the Shopify API is crucial for e-commerce businesses that need to integrate their store data with marketing automation tools. Developers can use the API to sync customer information, order history, and product details with external marketing platforms, or build custom marketing functionalities directly into their Shopify stores. This allows for highly tailored marketing campaigns based on customer purchasing behavior and preferences. Shopify's extensive app ecosystem also provides numerous integrations with marketing services, making it a central hub for e-commerce operations.

   Best for: E-commerce businesses, integrating store data with marketing platforms, building custom e-commerce functionalities, and managing online sales and customer relationships.

   Explore the Shopify API profile.

7. 7. Salesforce Marketing Cloud — Enterprise marketing automation and CRM integration

   Salesforce Marketing Cloud is an enterprise-grade platform that offers a broad suite of tools for digital marketing, including email, mobile, social, web personalization, advertising, and journey management [source]. Its APIs enable deep integration with Salesforce CRM and other enterprise systems, allowing businesses to create highly personalized customer experiences across all touchpoints. Marketing Cloud is designed for large organizations that require sophisticated marketing automation, advanced analytics, and a unified view of the customer across sales, service, and marketing. Developers can leverage its APIs to automate complex workflows, manage customer data, and extend platform capabilities to meet specific business needs, often in highly regulated industries.

   Best for: Large enterprises, comprehensive CRM integration, advanced multi-channel marketing automation, and businesses requiring a unified customer view across Salesforce products.

   Explore the Salesforce Marketing Cloud API profile.

Side-by-side

How to pick

Selecting an alternative to Klaviyo API involves evaluating your specific business needs, technical capabilities, and long-term marketing strategy. Consider the following factors when making your decision:

• Primary Communication Channels: If your marketing strategy heavily relies on email and SMS, platforms like Mailchimp or even Salesforce Marketing Cloud might be suitable, depending on your scale. If you require broader multi-channel engagement, including push notifications, in-app messages, or web personalization, Braze or Iterable offer more comprehensive solutions. For highly customized SMS and voice interactions, Twilio provides the underlying programmable infrastructure.

• Scale and Complexity: For small to medium-sized businesses with straightforward email marketing needs, Mailchimp often provides a cost-effective and user-friendly option. As your business grows and requires more sophisticated customer journeys, real-time personalization, and extensive data integration, platforms like Iterable or Braze become more relevant. Large enterprises with complex organizational structures and deep CRM integration requirements may find Salesforce Marketing Cloud to be a better fit.

• Integration Ecosystem: Evaluate how well the alternative integrates with your existing technology stack. If you operate an e-commerce store, the Shopify API is fundamental for syncing data. If you're building a mobile or web application, Firebase Cloud Messaging offers native integration for notifications. Consider the availability of pre-built connectors, SDKs, and the flexibility of the API for custom integrations. A platform with a robust API and extensive documentation can reduce development time and effort.

• Developer Experience: Assess the quality of the API documentation, the availability of SDKs in your preferred programming languages, and the support resources offered. Platforms with active developer communities and clear examples can significantly improve the developer experience. Twilio, for example, is known for its developer-centric approach and extensive documentation for building communication features programmatically.

• Pricing Model: Understand the pricing structure of each alternative. Klaviyo's pricing scales with contacts and email/SMS sends. Alternatives may offer different models, such as per-user, per-message, or feature-based pricing. Compare the total cost of ownership, including potential hidden fees, and how it aligns with your budget and anticipated growth. Many platforms offer free tiers or trials, which can be useful for initial evaluation.

• Data Management and Personalization: If advanced customer data platform (CDP) capabilities, granular segmentation, and AI-driven personalization are critical, platforms like Braze and Iterable excel in these areas. They allow for a deeper understanding of customer behavior and the creation of highly targeted campaigns. Ensure the platform can handle your data volume and complexity while providing the necessary tools for actionable insights.

• Compliance and Security: For businesses operating in regulated industries or handling sensitive customer data, verify that the alternative platform meets your compliance (e.g., GDPR, CCPA, SOC 2) and security requirements. Review their data privacy policies and security certifications to ensure they align with your organizational standards.