Google Analytics 4 (GA4)

GA4 replaced Universal Analytics, whose standard properties stopped processing new data in July 2023. The biggest change is the model underneath: everything, from a page view to a form submission, is an event with optional details attached. Sessions and users are built from those events rather than being the basic unit.

GA4 is not the same as Google Search Console. Search Console shows how your site performs in Google Search before the click: queries, impressions and positions. GA4 shows what happens on the site after visitors arrive, from any source.

How it works

You add a Google tag to every page, directly or through Google Tag Manager. It sends events to your GA4 property as people browse. Some events are collected automatically, such as page views and first visits, and enhanced measurement can add scrolls, outbound clicks and file downloads. You mark the events that matter most, such as a completed enquiry, as key events, which is GA4's name for what it used to call conversions.

Reports then group those events by traffic source, page, device and other dimensions. Where your site uses a cookie consent banner, GA4 only collects full data from people who agree, and Google's consent mode can adjust how the tag behaves for those who decline.

A few behaviours surprise new users. Reports can take a day or more to settle, so very recent figures may change. Some reports apply thresholds that hide small numbers to protect privacy, and large date ranges in explorations can be based on a sample of data. Detailed data used in explorations is kept for only two months by default, and at most 14 months in the free version, so it is worth checking the retention setting in admin early. To check your own setup, open the realtime report, visit your site from a phone, submit a test enquiry and confirm both the page view and the key event appear; then filter out or delete that test so it does not count as a real lead.

Example

A travel agency installs GA4, marks "booking request sent" as a key event and tags its newsletter links with UTM parameters. After a month it can see that most booking requests come from organic search and the newsletter, while a paid social campaign brings many sessions but few requests. That evidence shapes next quarter's budget.

The agency also discovers a setup gap. Phone calls, its most common way to book, were invisible in GA4 because nobody tracked taps on the phone number. Once it marks those taps as a key event, the organic search share of bookings becomes even larger, and a page about group tours that seemed weak turns out to drive many calls.

Why it matters for your business

GA4 costs nothing and answers the questions that drive marketing spend: which channels bring customers, which pages lose them, and whether a change helped. The trade-offs are a learning curve, reports that do not always match other tools, and legal obligations around consent and data transfers in the EU under GDPR. Some small businesses only need a handful of numbers and choose a simpler, privacy-focused analytics tool instead. Spending an hour on a clean setup at the start, with key events, internal traffic filters and consent handled, saves far more time than fixing confusing data later.

Common mistakes

• Installing GA4 but never marking any key events, so it reports traffic but not results.
• Loading the tag before the visitor has given consent where the law requires consent first.
• Expecting GA4, Search Console and ad platforms to report identical numbers when they count different things.
• Leaving internal traffic from your own staff in the data, which inflates sessions and engagement.

Questions people ask

Is Google Analytics 4 free?

Yes, the standard version of GA4 is free and is what most small and mid-sized businesses use. Google also sells a paid enterprise edition with higher limits and service guarantees, aimed at very large organisations with heavy data needs.

What is the difference between GA4 and Universal Analytics?

Universal Analytics was built around sessions and page views, while GA4 records everything as events. Universal Analytics no longer processes data, so GA4 is the only one of the two still running. Some metrics, including bounce rate, are defined differently, so old and new numbers are not directly comparable.

Do I need cookie consent for GA4?

In the EU and UK you generally need consent before GA4 sets its cookies or similar identifiers. The UK has a narrow exemption for cookies used only for your own statistics, but it does not cover providers that use the data for their own purposes. Many sites use a consent banner with Google's consent mode. Check the rules that apply where you operate and record your approach in your privacy policy.