Retargeting Strategies Without Third-Party Cookies: The 2025 Marketer’s Guide

For years, digital advertising has relied on third-party cookies to track user behavior and deliver personalized ads. But by late 2025, that era will officially end. Google’s Privacy Sandbox initiative is phasing out third-party cookies in Chrome, following similar actions by Safari and Firefox (Google, 2025a).

This massive shift changes how marketers retarget users online. If you’re not preparing for this now, you risk losing targeting accuracy, audience reach, and revenue. The good news? There are powerful, privacy-first alternatives available.

In this article, we’ll explore how to build effective retargeting strategies without third-party cookies, using first-party data, server-side tracking, and trusted tools.

“Retargeting without cookies isn’t a setback—it’s an opportunity to build deeper, consent-driven customer relationships.”
– Mr. Phalla Plang, Digital Marketing Specialist

What Are Third-Party Cookies? And Why Are They Going Away?

Third-party cookies are small pieces of code set by domains other than the one you’re visiting. They allow advertisers to track your browsing behavior across websites for targeting and analytics.

But concerns around user privacy, data misuse, and lack of transparency led to regulatory and browser-level changes. In 2025, Google Chrome—the world’s most-used browser—is eliminating support for these cookies (Google, 2025a).

This means traditional retargeting methods—like Google Display Network remarketing, Facebook dynamic product ads (DPA) relying on pixel-only setups, or banner ad retargeting via AdSense—will be affected.

How Will Retargeting Work Without Cookies?

Without third-party cookies, you’ll need to use first-party data, server-side tracking, and consented user interactions to build audiences.

Your new retargeting stack should be built around:

• First-party data collection (emails, site activity, purchases)
  
• Server-side APIs (Meta Conversions API, Google Enhanced Conversions)
  
• Consent-based audience segmentation
  
• Contextual and behavioral signals
  
• Walled garden platforms (Meta, Google, Amazon)
  

Let’s explore each of these in detail.

1. Use First-Party Data as the New Foundation

First-party data is information collected directly from your users. This includes:

• Email addresses from newsletter signups
  
• On-site behavior tracked with tools like GA4
  
• Purchase history from your CRM or eCommerce platform
  
• User preferences collected via surveys or preference centers
  

Unlike third-party cookies, first-party data is owned by you and not affected by browser restrictions.

According to HubSpot (2024), 74% of marketers in 2025 say first-party data will be their most valuable asset for personalization.

Pro Tip: Use tools like:

• Klaviyo for capturing and activating email + behavioral data
  
• Segment for customer data platforms (CDPs)
  
• GA4 for first-party event tracking
  

2. Implement Server-Side Tracking (CAPI & Enhanced Conversions)

Cookies used to live in the browser. Now, data must travel through server-to-server APIs for accuracy and compliance.

Two essential technologies:

• Meta Conversions API – Sends conversion events directly from your server to Meta, bypassing the browser
  
• Google Enhanced Conversions – Matches hashed first-party data (like email) with logged-in Google users for more accurate attribution
  

This server-side tracking approach ensures:

• Better data accuracy
  
• Cookie-independent audience building
  
• Compliance with GDPR/CCPA through hashed data transfer
  

“Server-side tracking future-proofs your campaigns against cookie loss while improving attribution clarity.”
– Mr. Phalla Plang

3. Build Authenticated, Logged-In Experiences

One long-term solution is to encourage user logins or account creation. Authenticated users provide:

• Consent
  
• Persistent identifiers (email, user ID)
  
• Accurate behavioral data
  

Platforms like Amazon, Facebook, and Google already do this. Marketers should follow by:

• Offering gated content
  
• Encouraging wishlists or saved carts
  
• Providing loyalty benefits
  

This helps you build permission-based, persistent retargeting audiences.

4. Leverage Email & SMS Retargeting

With cookies gone, your email list becomes gold. Use it to:

• Run remarketing sequences (abandoned carts, re-engagement emails)
  
• Create Custom Audiences in Meta or Customer Match in Google Ads
  
• Send SMS reminders using tools like Postscript or Attentive
  

Example: Upload your email list into Meta Ads Manager and retarget those users across Facebook and Instagram—without needing cookies (Meta, 2025).

5. Contextual Targeting: Smart Ads Without Tracking

Instead of following the user, serve ads based on content relevance. This is called contextual advertising, and it’s making a big comeback.

Example: If a user reads an article on “Running Shoes,” show them an ad for Nike sneakers—no need to know who they are.

Tools like:

• GumGum (AI-powered contextual ads)
  
• StackAdapt (programmatic ad platform with contextual segments)
  

…help deliver relevant ads based on page content, not user history.

6. Use Google’s Privacy Sandbox Tools

Google’s Privacy Sandbox includes APIs that offer cookie-free solutions:

• Topics API: Assigns interest categories to users (like “fitness” or “tech”) based on recent browsing
  
• Protected Audience API (FLEDGE): Stores remarketing data in-browser and serves personalized ads anonymously
  
• Attribution Reporting API: Tracks conversions without tracking users
  

These APIs are being adopted by advertisers using platforms like Display & Video 360 (DV360) and Google Ads (Google, 2025b).

7. Focus on CRM-Based Retargeting

Your CRM is now your central targeting hub. Platforms like:

• ActiveCampaign
  
• Salesforce Marketing Cloud
  

…allow you to:

• Segment users by behavior or lifecycle stage
  
• Trigger personalized email/SMS sequences
  
• Sync lists with ad platforms for matched audiences
  

This approach relies 100% on first-party data and user consent—perfect for the cookieless age.

8. Combine Retargeting with Predictive Analytics

AI and machine learning are reshaping retargeting. In the absence of cookie trails, use predictive analytics to:

• Score leads based on intent
  
• Forecast cart abandonment
  
• Trigger messages before a user bounces
  

Tools like:

• Blueshift (AI marketing automation)
  
• Optimizely (behavioral testing & personalization)
  

…can deliver preemptive engagement, reducing reliance on third-party retargeting entirely.

9. Strengthen Consent Management

You can’t collect first-party data without permission. Use a Consent Management Platform (CMP) like:

• OneTrust
  
• Cookiebot
  

…to ensure:

• Users opt into tracking and personalization
  
• GDPR and CCPA compliance
  
• Audit trails for regulators
  

In 2025, consent isn’t just ethical—it’s legally required for retargeting.

10. Adopt an Omnichannel Retargeting Strategy

Don’t rely on just ads. Use email, SMS, web push, chat, and even direct mail to bring users back. Omnisend (2025) found that campaigns using 3+ channels deliver 250% higher engagement rates than single-channel campaigns.

References

AdRoll. (2024). Retargeting Without Cookies: The Future of Personalization. https://www.adroll.com/blog
Google. (2025a). Privacy Sandbox for Developers. https://privacysandbox.com
Google. (2025b). Enhanced Conversions Overview. https://support.google.com/google-ads/answer/9888656
HubSpot. (2024). The State of Marketing Trends Report. https://blog.hubspot.com/marketing/trends
Meta. (2025). Meta Conversions API Integration Guide. https://developers.facebook.com/docs/marketing-api/conversions-api/
Omnisend. (2025). Omnichannel Automation Report. https://www.omnisend.com/blog/omnichannel-marketing-stats/