Content revised 21 October 2026.
Start with the question your website needs to answer. In GA4, metrics are numbers and dimensions describe them, so a useful review often combines both.
1. Users and sessions
Users estimate people who interacted with the site, while sessions measure periods of interaction. Compare them over a suitable timeframe and segment. A higher total is not automatically progress if the visits are irrelevant or measurement changed.
2. Engagement
GA4 defines an engaged session using time, key-event or page/screen-view conditions. Engagement rate can help flag a change, but it needs the page purpose and traffic source for context. A short visit can still succeed when someone quickly finds a phone number.
3. Key events
Mark an event as a key event when it represents an action important to the business, such as a confirmed enquiry or purchase. Verify the implementation and avoid treating every button click as a completed customer outcome. Compare the count and the session key-event rate where appropriate.
4. Landing-page performance
Landing page is a dimension identifying the first page visited in a session. Combine it with sessions, engagement and key events to see how entry pages support real tasks. Referral source is also a dimension rather than a performance metric. Keep definitions clear when presenting a “top metrics” report.
Official guidance: GA4 dimensions and metrics, GA4 key events guidance.