Thank you. With that, I would like to turn the call over to Andrew Zilli, Vice President of Investor Relations. You may begin.
Thanks. Good afternoon, and thanks for joining Klaviyo's first quarter 2025 earnings call. Our earnings press release, investor presentation, SEC filings, and a replay of today's call can be found on our IR website at investors.klaviyo.com. With me on the call today are Andrew Bialecki, Co-founder and CEO, and Amanda Whalen, CFO. As a reminder, our commentary today will include non-GAAP measures. Reconciliations to the most directly comparable GAAP measures can be found in today's earnings press release or earnings release supplemental materials, which can be found on our investor relations website. Additionally, some of our comments today contain forward-looking statements that are subject to risks, uncertainties, and assumptions, which could change. Should any of these risks materialize, or should our assumptions prove to be incorrect, actual company results could differ materially from these forward-looking statements.
A description of these risks, uncertainties, and assumptions, and other factors that could affect our financial results are included in our SEC filings, including our most recent annual report on Form 10-K and subsequent quarterly reports on Form 10-Q. Except as required by law, we do not undertake any responsibility to update these forward-looking statements. With that, I'll now turn it over to Andrew.
Thanks, Zilli, and thank you all for joining us today. Klaviyo delivered a strong start to 2025 with Q1 revenue of $280 million, representing 33% year-over-year growth. We now empower over 169,000 customers worldwide, from individual entrepreneurs to global enterprises, to build smarter digital relationships. We are a must-have omnichannel platform for businesses looking to connect with their consumers in a meaningful way and drive revenue. Our performance once again proved out three defining themes for Klaviyo. First, we are a growth company, and we are executing well on our strategy to deliver sustainable, efficient, long-term growth with notable momentum growing in the mid-market and above and expanding internationally. Second, our vertically integrated data-first approach with the powerful embedded Klaviyo Data Platform and fast pace of innovation are core differentiators.
Third, Klaviyo is uniquely positioned to redefine the next era of consumer engagement as the only CRM built for B2C businesses. The future of marketing is more personalized, but companies can only deliver on that if they know who their consumers are and where to best reach them. With B2C CRM, we've brought together multichannel marketing automation, customer service, and marketing analytics onto one AI-powered data platform. This allows companies to take action on their data and build long-term loyal consumer relationships across every touchpoint. B2C CRM positions Klaviyo to address a critical gap in the market, providing consumer brands with a system designed for their unique, high-volume, fast-paced needs. This is a natural evolution of our journey from a leading marketing automation platform to a comprehensive solution that unifies marketing, service, and analytics.
That's more personalization and less costly service interactions, delivering better outcomes for both consumers and brands. Klaviyo Marketing combines our messaging channels with campaigns, flows, forms, reviews, and more. It remains at the core of our platform, and in Q1, our team delivered several new features that leverage data and AI to make it even easier for brands to engage with their consumers across channels. This includes automated campaign follow-up to improve campaign re-engagement, brand voice consistency for email AI to automatically capture and apply unique brand guidelines to AI-generated content, and several new form features to drive better sign-up rates. We also recently introduced custom objects, which allows brands to define their own data structure with fully customizable properties. For example, a restaurant can create an object to capture reservation occasions, allowing them to store that on the consumer profile and leverage it for future engagement opportunities.
Currently, in limited availability, this feature is particularly important for larger brands and customers outside of e-commerce. We also launched automated conversations for SMS, which enables our customers to drive more sales with a tailored shopping experience by integrating campaigns and flows into SMS conversations. This enables our customers to collect more information from their consumers and use that information to provide product recommendations, making the interactions more engaging and personalized. Our commitment to innovating across our platform remains core to why a diverse set of customers choose Klaviyo. In Q1, we signed new or expansion deals with companies of all sizes, including Quip, Burt's Bees Baby, Mark Fisher, Kendo Beauty, and Features. We also power many of the fastest-growing companies in the consumer space.
Bain recently released their 2025 Insurgent Brands list, made up of companies with more than $25 million of annual revenue and growing 10 times their category average. Approximately 70% of the companies on the 2025 list are Klaviyo customers. Many companies are faced with a common challenge: the complexity brought by multiple-point solutions and older legacy systems that do not integrate together and make it extremely difficult to build lasting consumer relationships. This is driving a secular shift as companies are looking to modernize and consolidate their tech stack to enable a faster and more personalized consumer experience. Our modern vertically integrated platform positions Klaviyo well as companies of all sizes look to consolidate onto a unified data-powered platform. The more complex use cases that often come with larger brands play to Klaviyo's strengths.
Our platform can handle the scale, security requirements, and multi-country needs of many larger customers, and our API-first design offers the flexibility to support a wide range of use cases. Our competitive position against the legacy marketing clouds has never been stronger, as evidenced by several notable new mid-market and enterprise customer wins. One great example of this is a deal we signed in Q1 with the Hershey Company. The team was seeking a more modern and intuitive marketing platform for email and SMS for their direct-to-consumer commerce platforms. They also wanted marketing analytics for their Hershey's Chocolate World destination and their shop, Hersheys.com e-commerce platform, and chose Klaviyo as their partner to drive this forward. We also welcomed Belkin, a leading consumer electronics brand, to Klaviyo in Q1. The amount of manual development work required by their legacy marketing cloud was slowing down the marketing team's efforts.