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Vol. 1 · Ed. 2026
CyberGlossary
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Entry № 1286

Topics API

Was ist Topics API?

Topics APIA Privacy Sandbox API in Chrome and Android that derives a small set of high-level interest topics from the user's recent browsing locally on the device, exposing them to participating sites instead of cross-site tracking identifiers.

The Topics API is a Privacy Sandbox component that replaces third-party-cookie-based behavioural interest signals with a locally derived, low-resolution interest taxonomy. Chrome (and Android) infers, on device, up to a few coarse topics — drawn from a public taxonomy of a few hundred categories such as 'Sports/Soccer' or 'Travel/Hotels & Accommodations' — based on the top-level hostnames the user has visited over the past few weeks. When a caller invokes `document.browsingTopics()`, the browser returns a small random sample of recent topics (with random noise to limit linkability), but only for hostnames that were observed by that caller in the past. This means a fingerprinter sitting on a single site cannot ask for topics on behalf of unrelated callers, and a site cannot use the topics as a stable identifier. Critics — Mozilla, Brave, the EFF, several DPAs — have argued the API still reveals more than necessary and effectively endorses behavioural advertising at the browser level. Google launched Topics for general availability in Chrome in 2023 and on Android in 2024; uptake by ad-tech players grew through 2024–2025 in tandem with Privacy Sandbox.

● Beispiele

  1. 01

    An ad-tech vendor calls `document.browsingTopics()` from its tag on a sports site, receives `Sports/Soccer` for that user, and uses it as a contextual signal.

  2. 02

    A regulator's analysis observes that, even with topic noise, frequent callers can build short-lived behavioural cohorts and flags the API for further review.

● Häufige Fragen

Was ist Topics API?

A Privacy Sandbox API in Chrome and Android that derives a small set of high-level interest topics from the user's recent browsing locally on the device, exposing them to participating sites instead of cross-site tracking identifiers. Es gehört zur Kategorie Datenschutz der Cybersicherheit.

Was bedeutet Topics API?

A Privacy Sandbox API in Chrome and Android that derives a small set of high-level interest topics from the user's recent browsing locally on the device, exposing them to participating sites instead of cross-site tracking identifiers.

Wie funktioniert Topics API?

The Topics API is a Privacy Sandbox component that replaces third-party-cookie-based behavioural interest signals with a locally derived, low-resolution interest taxonomy. Chrome (and Android) infers, on device, up to a few coarse topics — drawn from a public taxonomy of a few hundred categories such as 'Sports/Soccer' or 'Travel/Hotels & Accommodations' — based on the top-level hostnames the user has visited over the past few weeks. When a caller invokes `document.browsingTopics()`, the browser returns a small random sample of recent topics (with random noise to limit linkability), but only for hostnames that were observed by that caller in the past. This means a fingerprinter sitting on a single site cannot ask for topics on behalf of unrelated callers, and a site cannot use the topics as a stable identifier. Critics — Mozilla, Brave, the EFF, several DPAs — have argued the API still reveals more than necessary and effectively endorses behavioural advertising at the browser level. Google launched Topics for general availability in Chrome in 2023 and on Android in 2024; uptake by ad-tech players grew through 2024–2025 in tandem with Privacy Sandbox.

Wie schützt man sich gegen Topics API?

Schutzmaßnahmen gegen Topics API kombinieren typischerweise technische Kontrollen und operative Praktiken, wie in der Definition oben beschrieben.

Welche anderen Bezeichnungen gibt es für Topics API?

Übliche alternative Bezeichnungen: Browsing Topics API.

● Verwandte Begriffe