Google Analytics 4: the event-based model
Google Analytics 4 (GA4) replaced Universal Analytics with a fully event-based model: everything, including pageviews, is an event with parameters. It introduced engagement-based metrics, cross-platform measurement, and a different relationship with sampling and data retention. It is free and widely used, with consent and data-transfer considerations that depend on your region.
What this means
GA4 models all activity as events with parameters — pageviews, scrolls, clicks, and conversions are all events. Metrics like engaged sessions and engagement rate replace some Universal Analytics concepts, which is why headline numbers shifted when sites migrated.
What to weigh
GA4 is free, deeply integrated with Google's ad and BigQuery ecosystem, and built for cross-platform measurement. The considerations are the usual ones for a third-party analytics platform: consent for cookie-based collection, data retention settings, and region-specific data-transfer questions. Read its definitions before comparing its numbers to another tool.
- Everything is an event with parameters
- Engagement-based metrics replace some UA ones
- Consent + data-transfer questions are region-specific
How it appears in analytics and logs
GA4 numbers often differ from Universal Analytics or other tools because the model changed (events, engaged sessions). Differences are usually definitional, not bugs.
Diagnostic use case
Understand GA4's event model and engagement metrics so its reports are read correctly, and weigh its consent/retention settings for your context.
What WebmasterID can help detect
WebmasterID is a privacy-first, first-party alternative for the AI-search era; this page explains GA4 even-handedly so a migration decision is informed.
Common mistakes
- Comparing GA4 numbers to Universal Analytics as if defined the same.
- Assuming default retention/consent settings fit every region.
- Reading definitional differences as tracking bugs.
Privacy and accuracy notes
GA4 is a third-party, Google-operated platform; consent and international data-transfer questions apply and vary by region. This page is factual, not legal advice.
Related pages
- Plausible: lightweight, privacy-focused analytics
Plausible is an open-source, cookieless, privacy-focused analytics tool. It deliberately keeps a small script and a simple metric set (visitors, pageviews, sources, top pages) and avoids cookies and cross-site identifiers. The trade-off is intentional: less granularity and individual-level depth in exchange for simplicity and a smaller privacy surface.
- The page_view event: the base of web analytics
page_view is the event fired when a page loads. It is the base of almost every web-analytics model: sessions, pageviews, and most reports build on it. In classic sites the tracker fires it automatically on load; in single-page apps you fire it on each route change. Its properties (path, title, referrer) drive most downstream reports.
- GDPR and web analytics: the practical picture
The GDPR governs processing of personal data of people in the EU. For analytics that means: identifiers and IP addresses can be personal data, consent is often required for cookie-based tracking, and minimisation matters. Cookieless, first-party, anonymised measurement reduces the surface — but this is a factual overview, not legal advice.
- Compare: Google Analytics
How WebmasterID differs from GA.
Sources and verification notes
Last reviewed 2026-06-24. Facts are checked against primary/official sources where available; uncertain specifics are marked “Data not yet verified” rather than guessed.