NYSE: KVYO

We purpose-built the KDP as a centralized, scalable, and flexible data store that allows our customers to intelligently aggregate and process first-party consumer profile and event data without friction. Building upon our robust data infrastructure, we developed tools, initially focusing on marketing automation, where we revolutionized email practices. While our KDP began with a focus on email marketing capabilities, we now incorporate text messaging and WhatsApp channels, Reviews, Marketing Agent, Klaviyo Service, Klaviyo Analytics, and others.

In early 2025, we defined and introduced a new category of customer relationship management solutions built exclusively for business-to-consumer (“B2C”) companies. We announced Klaviyo B2C CRM, a unified platform that combines marketing, service, analytics, and our data platform into a single system designed to meet the high-volume, fast-paced needs of consumer companies. Klaviyo B2C CRM enables businesses to manage interactions across channels and touchpoints, supporting more personalized and consistent consumer experiences. During 2025, we also expanded our offerings beyond marketing to address customer service use cases. We introduced a suite of capabilities integrated with our platform for service teams, including Customer Agent, Customer Hub, and Helpdesk, which are purpose-built for B2C companies. These offerings reflect our view that customer experience spans both marketing and service functions and benefits from a shared system of record and action.

In September 2025, we launched Marketing Agent and Customer Agent, which leverage Large Language Models (“LLMs”) and other generative artificial intelligence technologies. These capabilities are designed to help consumer companies apply AI in practical ways by using real-time consumer data, enabling immediate action, and continuously learning which actions drive improved business outcomes. Together, these capabilities position Klaviyo to address key gaps in the market for B2C companies seeking a unified, data-driven platform to understand their customers, engage effectively, and support long-term growth. Klaviyo is able to do this for three reasons: (1) we capture the real-time consumer context needed to make automated interactions relevant, (2) we have the infrastructure to help businesses take

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action immediately, and (3) our systems can learn which actions drive the best outcomes in response to consumer behavior. Klaviyo makes it easy for businesses to know their customers, activate their data, and grow faster.

Advances in AI are enabling businesses to operate with greater speed, quality, and accessibility across consumer-facing functions. AI-driven capabilities reduce operational bottlenecks, allowing teams to execute more quickly; generate marketing and service experiences that perform at or above historical manual benchmarks and improve over time; and expand access to sophisticated capabilities through natural-language interfaces and emerging digital channels. As these developments converge, consumer expectations are evolving toward more personalized, responsive, and continuous interactions. Klaviyo’s platform is designed to support this shift by enabling companies to deploy consumer-facing agents informed by first-party data, deliver individualized experiences across owned channels, and improve team efficiency through increased automation of marketing and service workflows. These capabilities rely on a unified consumer profile and the ability to act on data in real time, which Klaviyo provides through its integrated platform architecture.

Our strategy is to build the autonomous future for B2C companies. We will build that future by delivering an integrated platform that enables marketing, service, and analytics to operate with increasing autonomy on the KDP. We believe this approach supports market expansion, deeper multi-offering adoption, increased usage through automation, and a durable, subscription-based revenue model which is primarily priced based on fixed consumer profile tiers which aligns with consumer outcomes.

While we started in the eCommerce vertical, we have expanded and found organic growth in other verticals, such as education, events and entertainment, restaurants, and travel, as well as from business-to-business (“B2B”) companies. Our open and flexible platform allows for companies of any size to build consumer experiences, and as of December 31, 2025, we had efficiently scaled to over 193,000 customers. See the section titled “Key Performance Metrics – Customers” for additional information on how we define customers.

We generate revenue through the sale of subscriptions to our customers for the use of our platform. Our subscription plans are tiered based on the number of active consumer profiles stored on our platform and the number of emails, text messages and WhatsApp messages sent as well as customer tickets and conversations through Klaviyo Service. We do not price based on seats. We currently permit our customers to send unlimited push notifications, which are included as part of our email subscription plan. Active consumer profiles are identified profiles that can be reached via at least one enabled marketing channel in Klaviyo; this means the profile is not suppressed, either by revoking consent or being rendered undeliverable. The vast majority of our subscription plans today are monthly.

Our land-and-expand strategy aligns our success with that of our customers. As our customers grow, they use more active consumer profiles and send more messages like emails, text messages, and WhatsApp messages, which naturally increases their usage of our platform. Our revenue also expands when our customers add additional marketing channels, such as text messaging, mobile push and WhatsApp, and additional use cases, such as Customer Agent, Marketing Agent, Marketing Analytics, and Advanced KDP, or when their other companies, business units, and geographies start using our platform.

Our go-to-market strategy is primarily product-led, and we attract the majority of our new customers through inbound channels, such as word-of-mouth, agency partnerships, and platform integrations. We have built a large and growing ecosystem of major eCommerce platforms, agency partnerships, and developers, which helps us efficiently attract new customers. Once customers access the Klaviyo platform, they can easily integrate with more than 350 third-party data sources to import and explore their first-party data and design and run campaigns and automations, providing rapid time-to-value.

When we first launched our platform, we intentionally focused on serving entrepreneurs and small and medium-sized businesses (“SMBs”). As our customers have scaled and become mid-market companies and larger enterprises themselves,

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their success with Klaviyo has attracted more interest from similarly sized businesses that are looking to drive better engagement with their consumers. As such, we have continued to build out a sales team to focus on mid-market and enterprise customers.

We grew our revenue 31.6% year-over-year, from $937.5 million in 2024 to $1,234.0 million in 2025. Our net losses for 2024 and 2025 were $(46.1) million and $(31.8) million, respectively, representing a year-over-year decrease of (31.2)%. This decrease in net loss year-over-year was mainly driven by an increase in revenue. We grew our gross profit 28.7% year-over-year, from $716.2 million in 2024 to $921.5 million in 2025, representing gross profit margins of 76.4% and 74.7%, respectively.

Our Actionable Infrastructure

We built Klaviyo to provide businesses of all sizes powerful technology that captures, stores, analyzes, and predictively uses data to drive measurable, high-value outcomes. Our actionable infrastructure collects and organizes consumer profile and event data into a single system of record. It uses that data to support predictive insights and personalized actions, with interactions generating additional data that can improve future outcomes. Klaviyo brings three powerful components together:

Data Platform. Our customers grow by finding consumers, keeping them, and selling them more over time. Doing that well requires knowing who a consumer is, what they bought, what they looked at, what they abandoned, and when they did it. Our data platform combines profile data, such as identity and preferences, with event data such as browsing, purchasing, returns, and support interactions. By keeping both types of information current in one system, businesses can group customers into audiences that update automatically and respond immediately when a customer takes an action. Our platform is optimized for large volumes of data, delivers sub-second-level accessibility, and provides extremely high levels of personalization and attribution. We built our data store from the ground up to be agile, unbound by specific schema or data structures. This industry-agnostic approach supports marketing, service, and analytics use cases and can be applied to new verticals in the future.

Intelligence Layer. Our intelligence layer applies statistical and machine learning techniques to generate predictions and recommendations based on customer profile and event data to help our customers prioritize audiences, personalize experiences, and evaluate performance in increasingly autonomous ways. It has built insight from billions of messages and trillions of events, allowing businesses to apply real-time context to historical behavioral patterns, create impactful customer experiences, and drive measurable results. As these results create more data to build the intelligence layer, the flywheel compounds.

Action Layer. Knowledge only matters if it turns into action. On top of our data and intelligence layers sits a comprehensive set of tools, AI agents, and features that enable our customers to easily turn consumer insights into revenue-driving actions without the need to hire expensive in-house engineers. Our action layer includes marketing, customer service, analytics, and generative AI capabilities that allow our customers to design and deliver personalized engagement across digital channels. Our platform also incorporates machine learning techniques to power predictive analytics, enabling businesses to estimate consumer lifetime value, predict next order dates, or assess churn risk. Together, these capabilities enable businesses to deliver contextually-relevant and personalized experiences throughout the entire consumer journey.

Many companies try to create similar consumer experiences by attempting to stitch together separate products for data storage, analysis, and action. We built these functions to work together as one system. Companies use Klaviyo to interact with their customers, those interactions build our database, and as that database grows, so do our intelligence capabilities. This closed loop is increasingly autonomous, giving businesses a unified, self-reinforcing system that drives intelligent, real-time action.

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Key Benefits of Our Platform

Klaviyo allows customers to effectively harness their first-party data to deliver valuable consumer experiences. This approach has enabled us to deliver the following key benefits:

•Granular segmentation with real-time action by unifying profile and event data. Our customer data store is designed to consolidate customers’ first-party data at scale, synchronizing and unifying data from over 350 integrations seamlessly into a single system-of-record. To provide companies with the information needed to engage consumers effectively, our data store is architected to handle large data sets and can combine and store the complete history of consumer profile and event data in real time.

•Vertical integration that enables fast execution. Our platform combines our centralized data layer, our front-end action layer, and our powerful intelligence layer in one vertically-integrated technology stack. This offers our customers the ability to store and rapidly analyze consumer data in real-time and send automated messages with targeting based on our intelligence, all within one place. Going forward, our vertically-integrated technology stack also gives us the ability to easily extend our platform into new channels and applications.

•Closed-loop learning. Klaviyo incorporates AI and machine learning into this vertically-integrated stack to continuously improve outcomes for our customers. Our intelligence layer has built insight from billions of messages and trillions of events, allowing businesses to use real-time context to create impactful consumer experiences and more data to drive more intelligence. This is all increasingly autonomous. Our customers can then use Klaviyo to harness these AI-powered insights to create content and intelligent automations across marketing and customer service use cases. For example, with Marketing Agent our customers can choose to accept agent-generated campaigns with little or no editing.

•Easy-to-use functionality purpose-built for business users of any technical skill level. Our platform gives business users of any technical skill level the ability to easily build consumer segments, personalize content, create new automations, run tests, engage with their consumers, and launch marketing campaigns with differentiated experiences. Our platform offers simple, one-click, drag-and-drop customizable templates for designing messages. It also offers generative AI tools for creating content and targeting communications, allowing our customers to easily create impactful experiences customized to their unique brand. For advanced functionality, we offer a suite of tools to enable developers to build rapid automations for different use cases and quickly integrate with other systems efficiently, all from a simple and intuitive user interface.

•A flexible platform as preferences evolve. With over 350 integrations, Klaviyo was built from the beginning to be open, flexible, and adaptable to shifting consumer preferences, customer expectations, and new technologies. However these change over time, Klaviyo keeps our customers in control of their own data. As a single solution, Klaviyo enables customers to coordinate their consumer engagement strategy across digital channels, such as email, text, and WhatsApp messaging, as well as customer service touchpoints like live chats, without friction. Our omnichannel capabilities reduce the number of tools and integrations our customers need, increasing speed and efficiency while also reducing costs. Our vertical integration also allows us to easily expand into new channels, enabling our platform to evolve with consumer preferences.

•Rapid and efficient implementation with clear, attributable value to drive high ROI. Due to our pre-configured data model and automatic integrations, our platform offers rapid and efficient implementation. Meanwhile, due to our advanced technological architecture and vertical integration, we can quantify the amount of revenue that our customers generate with specific engagements through our platform, quickly and easily measuring their success. AI-powered automation further accelerates time to value by reducing manual setup and ongoing operational effort. As consumer interactions on Klaviyo generate attributable value, that continues to reinforce adoption.

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Our Growth Strategies

As we build the future for B2C companies, our growth strategy is to expand the types of consumer experiences our platform can deliver, increase the number of those experiences, and then deliver them with increasing quality and autonomy. We believe this approach supports market expansion, deeper multi-offering adoption, increased usage through automation, and a durable, subscription-based revenue model which is primarily priced based on fixed consumer profile tiers and aligns with consumer outcomes. As businesses rely more heavily on data-driven and AI-enabled systems to interact with consumers, we also believe our platform is positioned to support increased usage, broader adoption, and durable growth.

•Expand addressable markets and increase market share. We believe enterprise and international adoption represent significant growth opportunities as consumer companies seek a unified system to manage consumer experiences across marketing and service. As organizations consolidate tools and standardize on platforms that can operate at scale, we continue to see momentum among larger customers and in international markets, supported by investments in go-to-market capabilities, global infrastructure, and localization.

•Drive multi-offering adoption and deeper platform usage. We believe multi-offering adoption is a durable growth lever as customers consolidate marketing, service, and analytics on a shared data foundation. Customers that use multiple Klaviyo offerings are able to coordinate engagement more effectively across the consumer lifecycle, including marketing and service touchpoints, improving outcomes and increasing the value derived from the platform. As customers expand usage across additional offerings, channels, brands, and geographies, their reliance on our platform grows.

•Expand usage and monetization through AI and automation. We believe AI-powered agents and automation increase both the volume and value of interactions that customers run through our platform. As customers deploy agents to execute campaigns, respond to inquiries, and personalize engagement in real time, we expect increased platform usage driven by higher interaction frequency, broader use cases, and more autonomous execution.

•Maintain a durable model aligned with customer outcomes. Our business model scales as customers grow and engage more consumers. As customers increase interaction volume, adopt additional offerings, and rely more heavily on automation and AI-driven workflows, our revenue naturally expands alongside customer success, reinforcing long-term durability.

Overall, this amalgamation of growth strategies is designed to align with customer outcomes. Klaviyo’s economics scale as customers grow and engage more consumers, reinforcing long-term value.

Our Capabilities

By combining unified consumer profiles with automation and execution, Klaviyo makes it easy to turn consumer data into revenue-driving experiences with measurable impact across marketing, service, and beyond. Our vertically-integrated, highly-scalable and flexible platform unifies the data and action layers with our messaging infrastructure into one modern tech stack, providing all the capabilities and automation tools necessary to drive personalized consumer engagement:

AI Agents

Marketing Agent: Marketing Agent is an AI-driven, autonomous marketing assistant built into the Klaviyo B2C CRM platform. It is designed to automate and accelerate marketing strategy, content creation, and campaign execution for

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consumer companies, enabling teams to operate with greater efficiency and creativity. With Marketing Agent, customers can autonomously generate complete, on-brand marketing campaigns, flows and signup forms in minutes.

Customer Agent: Customer Agent is an AI-powered assistant that provides 24/7 support and selling across digital channels. It answers questions, resolves issues, and helps shoppers discover products and complete purchases. Powered by Klaviyo data, Customer Agent delivers personalized, real-time conversations at scale, helping businesses improve consumer experiences, increase conversions, and reduce inquiries handled by human teams.

Marketing

Email: Klaviyo enables businesses to send personalized email communications to their customers, leveraging a unified consumer profile and real-time behavioral data. Our email marketing solution includes a range of customizable drag-and-drop templates, automated campaign and workflow capabilities, Smart Send Time optimization to improve engagement, generative AI tools for content and subject line creation, and A/B testing to support performance optimization. Advanced segmentation and personalization features allow customers to target audiences based on behavior, preferences, and predictive insights, helping drive more relevant and effective engagements.

Text and WhatsApp messaging: Klaviyo’s platform includes robust mobile messaging capabilities that enable companies to engage consumers via text messaging, Rich Communication Services (“RCS”), and WhatsApp, all powered by our real-time consumer data and unified profile infrastructure. Text messaging allows businesses to deliver targeted, automated text campaigns—including promotions, alerts, and reminders—with broad reach and integration into omnichannel flows. RCS enables rich, interactive, branded messages with high-resolution media and engagement features, while automatically falling back to text messaging where RCS is unsupported, enhancing engagement without sacrificing delivery. WhatsApp further extends messaging to one of the world’s most widely used mobile platforms, enabling personalized, real-time conversational and campaign-driven interactions that complement email and text messaging communications and support global consumer engagement strategies.

Mobile app marketing: Our push notification channel allows customers to send personalized push notifications on iOS and Android devices to engage consumers with timely and relevant mobile app notifications to build omnichannel experiences.

Social: With Klaviyo’s acquisition of Gatsby in 2025, we enable companies to convert social media engagement into measurable growth. Klaviyo Social brings social interaction data—such as Instagram comments, direct messages, and tags—into the Company’s unified consumer profiles, enabling more personalization across channels. Klaviyo Social allows companies to grow owned contact lists directly from social platforms by capturing consented email and text messaging subscribers generated through social campaigns, and to use real-time audience synchronization to improve advertising efficiency across major platforms.

Reviews: Our Reviews add-on allows our customers to collect product reviews alongside consumer data and messaging in Klaviyo, delivering a more seamless experience across the customer lifecycle. Our AI tools also suggest review headlines for consumers based on their review content, and generate personalized review replies for our customers with the click of a button.

Our omnichannel approach allows our customers to communicate with their consumers in the manner that best serves their diverse business needs. By creating a single, holistic view of the consumer, we can help customers understand and communicate with their consumers across all channels. For example, some customers may choose to engage with consumers asynchronously through email with highly-segmented, personalized, and cost-effective messages. However, in some cases, such as notification of a flash sale, customers may choose to drive revenue through concise, action-oriented interactions delivered in real-time through text messaging, WhatsApp messaging, or push. Because our platform was purpose-built to help customers understand their consumers, our customers can leverage consumer profiles, event data, and

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AI-powered predictive analytics to deliver highly personalized messages across relevant communication channels, rather than through disparate and disjointed channels.

Service

Customer Hub and Helpdesk, along with Customer Agent described above, together form Klaviyo’s Service suite, designed to connect consumer-facing service experiences with Marketing on a single platform powered by data and AI. By unifying Service and Marketing workflows, these offerings enable businesses to engage consumers more consistently across the customer lifecycle, using real-time data and intelligence to inform more personalized, seamless interactions.

Customer Hub: Customer Hub is a consumer-facing portal that brings shopping, service, and personalization together in one place. Shoppers can track orders, discover products, redeem rewards, manage subscriptions, and get support using real-time, on-site personalization powered by Klaviyo data. Customer Hub helps businesses increase revenue, strengthen loyalty, and deliver more tailored consumer experiences.

Helpdesk: Helpdesk is an AI-powered workspace for managing consumer conversations across channels. Teams use Helpdesk to route inquiries, manage issues, and respond with full consumer context from Klaviyo data. By connecting service interactions with marketing, Helpdesk helps businesses operate more efficiently and deliver more connected consumer experiences.

Data and Analytics

KDP: The KDP is embedded within Klaviyo’s B2C CRM and available to all Klaviyo customers. The KDP unifies real-time and historical consumer data for marketing, customer service, and analytics—and it’s built into Klaviyo B2C CRM. It provides user-friendly tools to unify, enrich, transform data, run more advanced reporting and predictive analysis, and sync data into and out of Klaviyo at scale. Our KDP is built for businesses of all sizes and gives customers a unified, real-time view of consumers across their entire lifecycles.

Advanced KDP: Building on top of the features included to all customers through the KDP, the Advanced Klaviyo Data Platform provides an enhanced set of data capabilities for more advanced users. Additional features include data export to third-party destinations, no-code data transformations, customizable CLV predictive analytics, catalog insights to drive cross-sell, and more advanced segmentation like RFM (recency, frequency, monetary value) analysis.

Marketing Analytics: Our Marketing Analytics offering provides companies real-time, AI-powered insight into consumer purchase behavior so they can take action faster. Our predictive analytics features use AI and machine learning to drive valuable consumer insights related to consumer lifetime value, churn risk, and behavior forecasting, enabling businesses to make data-driven decisions that help them maximize revenue potential. Customers can benchmark their performance metrics against industry peers to identify optimization opportunities. These analytics capabilities integrate directly with our unified platform, enabling customers to immediately convert insights into targeted marketing campaigns and automated workflows that drive measurable revenue growth.

Our Features

Integrations: We integrate with a wide range of data sources such as retail and eCommerce platforms, including Shopify, WooCommerce, and Salesforce Commerce Cloud, to comprehensively replicate all historical profile and event data in Klaviyo and synchronize data going forward. These integrations allow our customers to create a complete consumer source of record, bringing additional profile and event information into Klaviyo with minimal engineering effort.

Segmentation: Our advanced audience segmentation allows businesses to create consumer segmentation based on all the consumer data they have available in Klaviyo, including purchase history, engagement levels, and Klaviyo-powered

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predicted customer lifetime value. The segmentation feature enables our customers to better target consumers with personalized engagement, and our AI tools allow our customers to quickly create segments using natural language inputs. Via Klaviyo’s outbound integrations, segments can be automatically pushed to ad networks to further target consumers or accessed via API to power actions in other systems.

Automation — Campaigns and Flows: Using our platform, businesses can build marketing campaigns, which deliver regular interactions to their consumers about new launches, sales announcements, newsletters, and more. With Klaviyo, customers can drive more revenue by building data-powered omnichannel campaigns that engage their consumers across every touchpoint. We offer pre-built templates for customers to choose from, and our platform has built-in generative AI capabilities to allow users to auto-generate email, text messaging, and WhatsApp messaging content and build automations using natural language inputs. Our platform also enables businesses to build flows, which are a sequence of automated actions, including messages, that are triggered when a consumer performs a specific action — such as joining a list, being added to a segment, making a purchase, or abandoning their cart. We also offer customers the ability to use AI-assisted natural language inputs to build and manage their flows with minimal human input needed. Our built-in attribution allows customers to quantify and understand the revenue impact of campaigns and flows.

Analytics and Benchmarks: Our predictive analytics features use AI and machine learning to drive valuable consumer insights related to consumer lifetime value, churn risk, and behavior forecasting. Our benchmark feature aggregates anonymized performance data across our customer engagement strategies and allows businesses to compare their performance to that of their industry peers. Business metric comparisons such as open rate, average cart value, and subscriber rate allow businesses to evaluate the effectiveness of their engagement strategy and identify key areas of opportunity.

Our Technology

The Klaviyo infrastructure was engineered to be cloud-native, consisting of a set of reusable primitives that enable tight vertical integration while remaining independent and extensible. From the beginning, it was designed to power many applications—starting with marketing—as well as intelligence use cases, beginning with machine learning and more recently generative AI.

Our data layer is the core of the Klaviyo platform and the foundation on which we built all our functionality. We built a composite data store that aggregates effectively unlimited amounts of data in a way suitable for transactional, analytical, and machine learning workloads. Event data allows customers to send behavior-triggered messages that keep consumers engaged with the right message at the right time. This industry-agnostic, data-first approach supports marketing, customer service, and analytics use cases and can be applied to any vertical that requires the combination of fast performance with real-time, predictive intelligence. The architecture of our data store runs an ingestion pipeline responsible for deduping, data augmentation, and identity resolution. This pipeline spawns an extensible projection mechanism in real-time as billions of facts and actions are ingested, enabling us to store the processed data in multiple formats and easily add new use cases.

This data layer feeds applications and agents that enable businesses to deploy predictive modeling and personalized engagement across the entire consumer journey without specialized engineering teams. These applications and agents are natively integrated with our data store and leverage sophisticated machine learning, giving businesses predictive insights like estimated customer lifetime value, next order dates, or churn risk. We have expanded our action layer to include Klaviyo Service, our AI-powered customer service offering, which enables businesses to manage and automate customer support interactions using the same unified consumer data that powers marketing and analytics.

Finally, our intelligence layer connects the insights contained in our database to the actions powered by our applications. Here, consumer interactions enrich the data store, improve the intelligence layer outcomes, and use those

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outcomes to drive more interactions. Our intelligence layer has built insight from billions of messages and trillions of events, allowing businesses to apply real-time context to historical behavioral patterns.

The overarching architectural decision to use independent reusable primitives across the data, action, and intelligence layers was key to providing the level of scalability, reliability, and performance that our infrastructure offers. The overall result is a system that grows more effective overtime, moving beyond simple automation tasks toward a fully autonomous system that empowers businesses to act on their data with unprecedented scale and speed.

Scalability

Efficient Computation and Storage: Our vertically-integrated platform is built for massive scale using cloud computing. In order to enable our customers to create dynamic, personalized experiences for their end users, we efficiently ingested and stored billions of events every day on average during 2025. We use this data to power personalization and send billions of messages each month across multiple channels, including email, text messaging, WhatsApp messaging, and push notifications.

Optimized for Large Data Sets: Our data store is optimized for large data sets with the capacity to combine and store our customers’ entire consumer history of profile and event data in real time without expiration of the ingested data. Architectural techniques such as data partitioning and indexing across natural query seams allow our platform to scale with our customers.

Reliability

We store all Klaviyo data in the cloud and use fundamental building blocks of that platform, such as elastic compute cloud instances, elastic load balancers, and block storage.

Our systems are designed to be redundant and most of the intra-system communication is done asynchronously, which allows us to achieve a high degree of reliability. We built redundancy in every level of the stack. For example, every sub-system runs on multiple data centers, reducing the dependency on a specific data center. Additionally, we have built extensive monitoring to detect and recover from incidents and alert for potential anomalies.

In addition to reliability, we also built our platform with message deliverability as a top concern. Our customers demand tools that help them maintain a trusted reputation with their consumers and channel providers, which we accomplish by delivering personalized experiences on time and in accordance with applicable laws, regulations, and best practices. To further ensure trust in delivery, we also provide features like guided warming, shared and dedicated sending internet protocol addresses, and a tight feedback loop with channel providers. We ensure a frictionless experience for our customers, and therefore a differentiated user experience, with this focus on the reliability and scale of our messaging platform.

Performance

Fast Access to Data: Our composite data store is engineered for scale and speed without requiring workarounds and limitations. Our strong data store performance is based on our projection architecture and the selection of multiple backing databases including technologies such as MySQL, PostgreSQL, Clickhouse, and S3. This allows us fast access to range and point queries, complex segmentation, and aggregations, such as the amount spent by a consumer over the last 30 days.

We have intentionally separated our action layer from our data stores through the implementation of rich front-ends including HTML, JavaScript, and CSS that use techniques like backend-for-frontend APIs and leverage content delivery networks to reduce latency in accessing data.

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Our Partner Ecosystem

Our partner ecosystem enriches our customer offerings and helps us reach a broader audience than we would be able to reach on our own. Our partner ecosystem includes commerce platforms, other technology companies, marketing agencies, systems integrators, and developers. Each constituent of our ecosystem contributes to the growth of our business increasing our collective reach, the depth of our integration portfolio, and the breadth of our customers’ first-party consumer data.

Commerce Platforms

Through our partnerships and data integrations with commerce platforms, we are able to aggregate and analyze our customers’ first-party consumer data in real-time to drive more and better insights for our customers. In July 2022, we completed a series of transactions to memorialize our strategic partnership with Shopify, which established Klaviyo as the recommended email solution for all Shopify Plus merchants. We also partner with most other major commerce platforms, including WooCommerce, Magento (Adobe), BigCommerce, Salesforce Commerce Cloud, PrestaShop, and Shopware. We have additionally integrated with Amazon Buy with Prime. Our platform integrations create value for customers across a variety of verticals beyond retail and eCommerce. For example, we integrate with Olo and Toast in the restaurant industry, Mindbody in the fitness and wellness industry, and Eventbrite, Cloudbeds, and Mews in the events industry. In January 2026, we also launched the Klaviyo application with OpenAI, allowing our customers to access their Klaviyo data right inside ChatGPT.

Other Technology Partnerships

We enhance our platform through our large technology partner ecosystem and robust library of integrations with other technology platforms, including Google, Meta, Zendesk, Gorgias, LoyaltyLion, Pinterest, and Canva. We have built a robust suite of over 350 pre-built integrations and native data sources that customers want connected to their Klaviyo hub. Customers can leverage our fast, easy-to-use integrations to synchronize real-time data from technology companies specializing in payments, credit cards, order management, support tickets, subscriptions, shipping, surveys, referrals, and reviews, among others. Through these integrations, we have been able to build comprehensive consumer profiles on behalf of our customers that include information on consumer spend and details on non-financial activities, such as interactions with customer service, website activity, loyalty, social media, and more.

Marketing Agencies and Systems Integrators

We have built a deeply-invested community of digital marketing agencies, systems integrators, freelancers, and other consulting partners who recommend their clients use Klaviyo to design, run, and measure their marketing campaigns. These agencies help our customers run effective campaigns using Klaviyo, and provide strategic guidance to help our customers achieve their goals utilizing our platform. Many of these partners develop in-house Klaviyo expertise, build Klaviyo-dedicated service offerings, and go-to-market as Klaviyo partners. We mirror the investment these partners have made in Klaviyo by offering them a partner program (including incentives and requirements), partner-specific tools, and dedicated training and support. Marketing agencies partner with us because our platform is able to help their clients more effectively target consumers, and in the process, the agencies are able to grow their own businesses.

Systems integrators support many of our customers and help them get started on our platform. In some cases, our systems integrator partners leverage our flexible and scalable APIs to build custom integrations and bespoke solutions for their customers.

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Developers

We provide many developer-friendly features, including a flexible data architecture, no data pre-configuration requirements, API reference documentation and guides, new SDKs and developer tools, a community forum for collaboration, and monthly newsletters to help developers stay informed on all upcoming releases. We offer several incremental features that serve developers, including the ability to run code hosted on our platform. As a result, when developers are using our platform to build and test code, they can do so without needing to set up separate hosting environments. We also provide developers with data sample generation tools, allowing them to run and test their code against real, anonymized datasets which we generate for them as sample sets, so that they do not have to identify, obtain and ingest relevant data sets for their work. Additionally, in 2025, we launched the Klaviyo Model Context Protocol (MCP) server, which seamlessly integrates with Klaviyo’s APIs, enabling both customers and AI-native developers to use AI clients to interact with Klaviyo data and skills.

Our Customers

Our platform serves businesses of all sizes, across industries and geographies. Our customers range from entrepreneurs and small and medium-sized businesses to mid-market businesses and enterprises. Today we have a strong presence in the retail and eCommerce vertical and see growth from international customers. As of December 31, 2025, we served over 193,000 customers, up from 167,000 customers as of December 31, 2024.

Our Go-To-Market Strategy

Our product-led growth motion has helped build a highly efficient go-to-market engine powered by our strong platform and fast time-to-value, with limited reliance on professional services teams for implementation. Our marketing activities are designed to build broad brand awareness, generate thought leadership and create demand and leads for our sales organizations within our target markets.

Our large and growing ecosystem of major eCommerce platforms, agency partnerships, and developers, helps us efficiently attract new customers. We primarily attract new customers through inbound channels based on our reputation and product quality, such as word-of-mouth, commerce platform partnerships, and agency partnerships. We have a customer first approach and have designed our platform with the north star of helping businesses improve their engagement and drive revenue. As we deliver significant measurable and attributable value to our customers, they have become powerful advocates of our solution which allows us to benefit from a strong word-of-mouth motion.

Many of our customers come through our self-service channel by simply coming to our website and signing up for our platform without the need for our sales team’s involvement. Customers can start with a free tier of our platform or land directly with one of our paid subscription tiers.

With geographic coverage across Americas, EMEA, and APAC, our sales organization serves prospective customers and existing customers of all sizes. In addition to our self-service model, we deploy a high-velocity inside sales team focused on new customer acquisition, a mid-market and enterprise sales team, and a customer growth team focused on maximizing customer value and introducing all Klaviyo SKUs. Our acquisition teams respond to inbound and partnership-referred leads while also supplementing this demand by going outbound directly to businesses to introduce Klaviyo. Our go-to-market motion targets decision makers participating in the marketing-spend cycle, including the chief marketing officer, chief customer officer, and other key functional marketing heads.

Our outbound sales motion and sales process for all customers is differentiated by the amount of tangible advice and recommendations we are able to provide. Using all available channels, including social, video, email, phone, text messages, and WhatsApp messages, we are able to deliver actionable insights to prospective customers that help them drive revenue growth.

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Customer Experience

As a customer-first organization, our customers are at the heart of everything we do. We believe that the customer experience, along with the value they derive from Klaviyo, differentiates us in the marketplace. We provide our customers a comprehensive set of capabilities and services that support their journey with us. As a partner that creates value, we earn our customers’ trust, and that trust helps drive net retention through renewals and expansion.

Our Customer Experience teams provide a wide range of services that help meet our customers’ needs, including the following:

•Starting from the beginning of their journey, our onboarding teams work quickly to get customers set up with the right configuration and features to meet their business goals.

•For our smallest customers, we offer self-service journeys that support and guide them from onboarding to adoption to expansion.

•For our largest customers, we offer white glove engagement, guiding them as a trusted advisor around best practices, industry trends, and new product features and functionality, helping them optimize their success with Klaviyo and ultimately drive their own growth.

•Our Customer and Partner Education Services team offers a range of services, from providing free ungated content via social channels, learning tutorials, and live virtual hands-on training sessions, to helping customers set up segmentation, flows, and campaigns.

•Our global support team provides 24/7 email and live chat support to ensure customers’ critical questions and issues are addressed quickly.

•We offer proactive deliverability monitoring to ensure our customers’ messaging consistently reaches their consumers, as well as strategic audits to guide our customers to optimize the platform usage through shifting priorities and external environment changes.

•We offer dedicated developer education and technical documentation as well as a developer-specific community to support and grow our developer ecosystem.

Because we are always striving to raise the bar, we have a robust listening framework to engage with our customers from large to small through dedicated programs, such as Customer Success at Scale, Voice of the Customer, and dedicated Customer Success Managers for our largest customers. With this ongoing feedback, we can continue to make impactful improvements to our platform and to the customer experiences we offer.

Competition

The market in which we compete is evolving and highly competitive. There are several established and emerging competitors that address specific aspects of our platform, but we believe that none of our competitors currently offer comparable solutions that have the comprehensive functionality of our platform. Our main competitors are:

•Marketing solution providers, such as Mailchimp and Braze;

•Large, consolidated marketing automation software providers, such as Adobe and Salesforce; and

•Data-focused vendors, such as providers of cloud data warehouses or operational database technologies, which provide data infrastructure but are not purpose-built for consumer data and lack the front-end application layer.

In addition, our competitors could merge or partner with one-another or strengthen cooperative relationships with strategic distribution and technology partners or other parties.

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Our market is fragmented, highly competitive, and continues to evolve. We believe that the key competitive factors in our market are:

•Fast time-to-value and ROI for customers;

•Ease of deployment, implementation, and use;

•Unified data architecture, with the ability to synchronize unaggregated, historical customer profile data with real-time event data in a single system-of-record;

•Integration with third-party applications, data sources, and open-source technologies;

•Breadth and depth of features and functionality;

•Quality and accuracy of data and predictive intelligence;

•Ability to support multiple use cases and verticals;

•Strength of sales & marketing and partnership efforts;

•Market vision and product strategy;

•Pace of innovation;

•Brand awareness and reputation;

•Performance, scalability, security, and reliability; and

•Quality of service and customer satisfaction.

The integration and adoption of AI technology, including generative AI and autonomous AI agents, is increasingly central to competitive positioning in our industry. Our ability to develop and integrate advanced AI functionality affects our competitive standing and market differentiation.

We believe that we compare favorably on each of these factors relative to our competitors. However, some of our competitors and potential competitors may be larger and have greater brand awareness, longer operating histories, larger marketing budgets and established marketing relationships, access to larger customer bases, and significantly greater resources for product development, including integrating and developing AI technology. Additionally, because our market is rapidly developing, it is possible that new entrants, particularly those with extensive resources, could introduce new products or services that compete in our market and better address the needs of our customers and potential customers. See the section titled “Risk Factors” section for a more detailed description of risks related to competition.

Intellectual Property

We believe that our intellectual property rights are valuable and important to our business. We rely on a combination of patents, trademarks, copyrights, trade secrets, license agreements, confidentiality procedures, non-disclosure agreements, employee disclosure and invention assignment agreements, as well as other legal and contractual rights, to establish and protect our proprietary rights. Though we rely in part upon these legal and contractual protections, we believe that factors such as the skills and ingenuity of our employees, the functionality and infrastructure of our platform and our business, and frequent enhancements to and expansions of our platform are more important contributors to our success.

As of December 31, 2025, we had 26 issued and allowed patents and 47 pending patent applications in the United States that cover various aspects of our business in the United States and abroad. Our issued patents are scheduled to expire between February 2042 and February 2044. These patents and patent applications are intended to protect our proprietary

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inventions relevant to our business. We continually review our development efforts to assess the existence and patentability of new intellectual property.

We have an ongoing trademark and service mark registration program pursuant to which we register our brand names and product names, taglines, and logos in the United States and internationally to the extent we determine appropriate and cost-effective.

As of December 31, 2025, we had 6 registered trademarks and 5 pending trademarks in the United States and 101 registered trademarks and 42 pending trademarks in non-U.S. jurisdictions. We also have registered domain names for websites that we use in our business, such as www.klaviyo.com and other similar variations.

In addition, we seek to protect our intellectual property rights by requiring our employees and independent contractors involved in development of intellectual property on our behalf to enter into agreements acknowledging that all works or other intellectual property generated or conceived by them on our behalf are our property, and assigning to us any rights, including intellectual property rights, that they may claim or otherwise have in those works or property, to the extent allowable under applicable law.

From time to time, we also incorporate certain intellectual property licensed from third parties, including under certain open-source licenses. See the section titled “Risk Factors” for a more comprehensive description of risks related to our intellectual property.

Regulatory Matters

We are subject to a number of U.S. federal and state and foreign laws and regulations that involve matters central to our business. These laws and regulations may involve privacy, data protection and information security, intellectual property, competition, consumer protection, taxation, anti-bribery, anti-money laundering and corruption, economic or other trade prohibitions or sanctions, or securities law compliance, or other subjects. Many of the laws and regulations to which we are subject are still evolving and being tested in courts and could be interpreted and applied in a manner that is inconsistent across jurisdictions and may also be inconsistent with our current policies and practices, any or all of which could harm our business. In addition, the application and interpretation of these laws and regulations are often ambiguous or inconsistent, particularly in the new and rapidly evolving industry in which we operate, and the extent to which they apply to us is at times unclear. For more information on the potential impacts of government regulations affecting our business, see the section titled “Risk Factors.”

Human Capital Resources

As of December 31, 2025, we had a total of 2,368 employees located in six countries, with the substantial majority of our employees located in the United States. We supplement our workforce with contractors and consultants.

To our knowledge, none of our employees is represented by a labor union or covered by a collective bargaining agreement. We have not experienced any work stoppages, and we consider our relations with our employees to be good. Our human capital resources objectives include, as applicable, identifying, recruiting, retaining, incentivizing, and integrating our existing and new employees. The principal purposes of our equity incentive plans are to attract, retain, and reward personnel through the granting of share-based compensation awards in order to increase stockholder value and the success of our company by motivating such individuals to perform to the best of their abilities and achieve our objectives.

Corporate Information

We were incorporated in 2012 under the name Klaviyo, Inc. as a Delaware corporation. Our principal executive offices are located at 125 Summer Street, 6th Floor, Boston, MA 02110, and our telephone number is (617) 213-1788.

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“Klaviyo” is our registered trademark in the United States, the European Union (the “EU”), the United Kingdom, Australia, and other jurisdictions. The Klaviyo design logo and our other registered or common law trademarks, service marks or trade names appearing in this Annual Report on Form 10-K are the property of Klaviyo, Inc. and are protected under applicable intellectual property laws. Other trademarks and trade names referred to in this Annual Report on Form 10-K are the property of their respective owners. We do not intend our use or display of other companies’ trade names or trademarks to imply an endorsement or sponsorship of us by such companies, or any relationship with any of these companies.

Available Information

Our website is located at www.klaviyo.com, and our investor relations website is located at https://investors.klaviyo.com. Copies of our Annual Report on Form 10-K, Quarterly Reports on Form 10-Q, Current Reports on Form 8-K, and amendments to these reports filed or furnished pursuant to Section 13(a) or 15(d) of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), are available, free of charge, on our investor relations website as soon as reasonably practicable after we file such material electronically with or furnish it to the U.S. Securities and Exchange Commission (the “SEC”). The SEC also maintains a website that contains our SEC filings. The address of the site is www.sec.gov. We use our https://investors.klaviyo.com and www.klaviyo.com websites, as well as our blog posts, press releases, public conference calls, webcasts, X (formerly known as Twitter) feed, Instagram page, Facebook page, and LinkedIn page, as a means of disclosing material nonpublic information and for complying with our disclosure obligations under Regulation FD. The contents of our websites are not intended to be incorporated by reference into this Annual Report on Form 10-K or in any other report or document we file with the SEC, and any references to our websites are intended to be inactive textual references only.