Understanding how third-party cookie updates affect Klaviyo tracking
You will learn
Learn how third-party cookie restrictions and other privacy protections affect Klaviyo web tracking.
Privacy protections can limit tracking across websites. First-party cookies are set for the website a person is visiting. Third-party cookies are used by other sites, such as advertising services embedded on that website. Browsers handle third-party cookies differently.
What changed?
Since iOS 14.5, Apple’s App Tracking Transparency requires apps to get permission before tracking people across other companies’ apps and websites for targeted advertising or advertising measurement, or sharing their data with data brokers. This is separate from browser restrictions on third-party cookies.
Chrome has not eliminated third-party cookies for all users. In April 2025, Google confirmed that users can continue to allow or block third-party cookies in Chrome’s settings. Third-party cookies are blocked by default in Incognito mode.
About customer-first data
Customer-first data is data that’s sourced directly from a prospect or customer. It includes both zero-party data (information that someone proactively gives to you, like their email address, phone number, or birthday) and first-party data (information observed by a brand about someone on their owned properties, like what products they clicked on your website). All customer-first data can be used to create special and personalized communications with individual users.
How data privacy changes affect Klaviyo
Isn’t Klaviyo a third party? Doesn’t that mean it’s all third-party data?
The answer to this is no. Although Klaviyo is a separate marketing platform, data you collect directly from your customers through Klaviyo is not third-party data. Klaviyo helps you collect, analyze, and build campaigns with customer-first data, using straightforward methods like forms for email address capture. You still need to use that data in line with applicable consent and privacy requirements.
Does this mean display ads won’t work anymore?
Nope! They’ll still work, but third-party prospecting and retargeting through display ads could be less effective. If brands can’t access as much rich data about individuals, it could make ad targeting more challenging and less efficient. Shorter attribution windows can also mean fewer conversions are credited to your ads, lowering reported return on ad spend (ROAS) even if sales are unchanged.
How do third-party cookie restrictions affect my ability to track user behavior with Klaviyo?
With more than 265,000 forward-thinking brands trusting Klaviyo for their ecommerce marketing, we maintain a modern platform that gives you control of your customer data so that you can focus on growing your business.
Klaviyo uses a first-party cookie on your website to recognize visitors and does not rely on third-party cookies for onsite tracking. You can use this browsing activity to personalize messages to subscribers, subject to applicable consent and privacy requirements.
First-party tracking is still affected by browser privacy settings. If a visitor blocks or clears cookies, or their browser expires them, Klaviyo may need to identify that browser again before it can associate later browsing activity with the same profile. Learn more about how Klaviyo identifies site visitors.
What else to look at
You may want to audit your other marketing technologies to check if they comply with the new data privacy standards. For example, check your services that provide cross-website user identity matching, exit intent email collection, and APIs that may send customer event data into Klaviyo.
Additional resources
- How to comply with data privacy laws
Learn some some best practices for complying with data protection regulations in your marketing.
- Data privacy and third-party data