cookieless-alternatives

Cookie-less Tracking Alternatives

Overview

The deprecation of third-party cookies by browsers and increasing consent-driven restrictions on first-party cookies are driving the advertising and analytics industries toward alternative measurement and targeting approaches. Google's Privacy Sandbox initiative, launched in 2019 and iteratively developed through 2024-2026, provides a suite of browser APIs designed to replace cross-site tracking functionality with privacy-preserving alternatives. Alongside browser-based solutions, server-side analytics and probabilistic measurement methods offer additional paths. This skill evaluates each alternative's privacy properties, technical requirements, and readiness for production use.

Privacy Sandbox APIs

Topics API

Purpose: Interest-based advertising without cross-site tracking.

How It Works:

1. Chrome observes the user's browsing activity (top-level page visits) locally on-device
2. Each week, the browser classifies visited sites into topics from a taxonomy of approximately 470 advertising-relevant categories
3. When an ad tech company calls the Topics API on a publisher's site, the browser returns up to 3 topics (one from each of the last 3 weeks)
4. Topics are selected with 5% random noise (a random topic is returned instead of the true one)
5. A caller only receives topics that it has also observed the user being interested in (on other sites where the caller was present)

Topics Taxonomy Examples:

Topic ID	Category	Level
1	Arts & Entertainment	1
57	Arts & Entertainment / Movies	2
86	Business & Industrial / E-Commerce	2
243	Shopping / Apparel	2
332	Sports / Team Sports / Football	3

Implementation for Pinnacle E-Commerce Ltd:

// Check if Topics API is available
if ('browsingTopics' in document) {
  // Observe: register this page visit for topic classification
  // The fetch call with {browsingTopics: true} both observes and retrieves
  const response = await fetch('https://ads.pinnacle-ecommerce.com/topics', {
    browsingTopics: true
  });
  const topics = await response.json();
  // topics = [{ topic: 86, version: "chrome.2:2:1", configVersion: "chrome.2", taxonomyVersion: "2", modelVersion: "1" }]
}