Google Analytics (GA4)

GA4 is Google's web analytics platform. It tracks who visits a website, how they got there, what they do once on the website, and whether they complete actions that matter to the business.

What it measures

The current GA4 is built around an event-based data model. Every interaction — a page view, a click, a form submit — is recorded as an event with associated parameters. This is a fundamental shift from the now-deprecated Universal Analytics (UA), which was built around sessions and pageviews.

Core dimensions and metrics

• Users — unique visitors (counted via cookies and/or signed-in Google accounts).
• Sessions — visit groupings; in GA4, a new session starts after 30 minutes of inactivity by default.
• Engagement rate — the percentage of sessions that lasted longer than 10 seconds, had a conversion event, or included two or more pageviews. (Replaces UA's bounce rate, which still exists in GA4 but as a derived metric.)
• Events — all interactions, automatically collected (page_view, scroll, click, etc.) or custom-defined.
• Conversions — events flagged as business-critical (form submits, purchases, phone calls). Note: "conversions" has been renamed to "key events" in GA4.
• Acquisition channels — where traffic came from: Organic Search, Direct, Referral, Paid Search, Social, Email, etc.

Setting up GA4 (briefly)

A small JavaScript snippet — the Google tag (gtag.js) — must be added to the website and triggered to load on every page. Best practice is typically to deploy it via Google Tag Manager. The tag then sends event data to Google's servers, which aggregate, process, and present it in the GA4 interface.

What GA4 is good at

• Cross-device and cross-platform tracking (web + app in a single property).
• Funnel and path analysis via the Explore section.
• Native integration with Google Ads, Search Console, BigQuery (free export), and Looker Studio.

Common organic reporting uses

• Organic landing pages — which pages bring in organic traffic and convert.
• Channel comparison — organic vs paid vs direct vs referral performance.
• Engagement quality — time on page, scroll depth, and engagement rate by source/medium.
• Geographic and device segmentation — where organic users are coming from and on what devices.
• Conversion attribution — how organic search contributes to revenue or leads, often in combination with last-click and data-driven attribution models.

Common pitfalls/limitations

• No backfilling of data — it can't backfill historical data from before installation. (Search Console, by contrast, can show data from before you verified the property.)
• Filters and exclusions behave differently from Universal Analytics. Internal traffic exclusion is configured per data stream.
• Sampling — large queries in standard GA4 may be sampled, not 100% accurate.
• Bot filtering is automatic — most known bots are excluded by default, but custom bots may not be, and can still slip through, occasionally skewing the data.
• Organic search often misattributed to direct traffic — sessions where the referrer is stripped (e.g., certain mobile browsers, privacy plugins, etc.) arrive with no source, so GA4 assigns them to the Direct channel. This inflates direct figures and deflates organic, making SEO impact harder to measure accurately.

When to pair it with other tools

GA4 tells you what happened on the site. To understand why, pair it with Google Search Console (search query and position data), and heatmap tools like Hotjar or Microsoft Clarity.

Analysis and data

Disclaimer: All information contained herein is for informational purposes only. It is not advice or instructional.