Google Analytics 4 (GA4): How to Measure Traffic and Conversions in 2026

Google Analytics 4 (GA4) is Google's free analytics platform for measuring how people find and use a website or a mobile app, built on a model where every interaction is recorded as an event. It shows how many users visit, where they come from (search, ads, social networks, email, AI assistants), which pages they view, how engaged they are and which actions, called key events, lead to business results such as sign-ups or purchases.

GA4 replaced Universal Analytics, which stopped processing data for standard properties on July 1, 2023. The change was more than a new interface: GA4 measures differently, so some figures are not directly comparable with the old tool. Understanding its logic is the first step to reading it correctly.

What is Google Analytics 4?

GA4 is organized in accounts and properties. A property collects data from one or several data streams: a website, an iOS app, an Android app. A tracking tag (the Google tag, installed directly or through Google Tag Manager) sends events to the property each time a visitor does something: views a page, scrolls, clicks a link, watches a video, submits a form, buys a product.

Some events are collected automatically, others through enhanced measurement (scrolls, outbound clicks, site search, file downloads), and you can create your own. Events you mark as important become key events, the GA4 name for what used to be called conversions.

How does GA4 differ from Universal Analytics?

Universal Analytics was built around sessions and page views. GA4 is built around users and events, which makes it possible to measure websites and apps in the same property. Bounce rate, central in the old tool, has been redefined: in GA4, an engaged session lasts more than 10 seconds, includes a key event or includes at least two page views, and the bounce rate is simply the share of sessions that are not engaged.

GA4 also relies more on modeling. With consent mode, it can estimate part of the behavior of users who refuse cookies. Reports may apply thresholds to protect privacy, and standard properties keep detailed event data for two or fourteen months, depending on the setting. For longer history and custom analysis, GA4 offers a free export to BigQuery.

What are the main GA4 reports and metrics?

• Acquisition: where users and sessions come from, by channel, source, medium and campaign.
• Engagement: pages and screens viewed, events, engagement time, engagement rate.
• Monetization: e-commerce purchases, revenue, items viewed and added to cart.
• Retention: new versus returning users and how long they keep coming back.
• Explorations: custom analyses such as funnels, paths, segments and cohorts.

The default channel group assigns each visit to a channel (organic search, paid search, direct, referral, organic social, email and others) using its source and medium. It is the starting point for reading website traffic by source.

How to set up GA4 correctly

Create a property and a web data stream, then install the Google tag on every page, ideally through Google Tag Manager. Check that enhanced measurement is active, define your key events (lead form, demo request, purchase), and add e-commerce events if you sell online. Set data retention to fourteen months, exclude internal traffic and declare any domains that should not appear as referrals.

Then connect the tools around it. Linking GA4 with Google Search Console adds reports on organic queries and landing pages, and linking it with Google Ads imports ad costs and conversions. Use UTM parameters on every campaign link you control, so that email, social and partner traffic is attributed correctly.

Why GA4 matters for SEO and GEO

GA4 is where you see what search visibility becomes once people arrive: which pages attract organic traffic, how engaged those visitors are and whether they convert. Search Console shows what happens before the click, GA4 what happens after. Together, they tell you which content earns its rankings.

GA4 also helps measure visits from AI assistants. Sessions referred by ChatGPT, Perplexity, Gemini or Copilot appear with their source in acquisition reports, and a custom channel group can isolate them; our page on AI referred traffic explains how. Part of this traffic arrives without referral data and is counted as direct, so treat the figures as a minimum. Sorank's GEO and SEO dashboard connects Google Search Console and Google Analytics to show Google traffic and AI traffic in one view.

Common GA4 mistakes

The most frequent mistake is leaving GA4 with its default setup: no key events, two months of data retention, internal visits counted. Others are comparing GA4 and Universal Analytics figures as if they measured the same thing, double tagging that inflates page views, forgetting UTM parameters, and reading the total traffic without looking at channels or engagement.

Conclusion

Google Analytics 4 is Google's free, event-based analytics tool for websites and apps. It shows where visitors come from, what they do and which actions create value. Set up properly, with key events, longer retention, Search Console and Ads links and clean campaign tagging, it becomes the reference for measuring the results of SEO and the growing traffic from AI assistants.

To go further, read our pages on website traffic, AI referred traffic and Google Search Console. Reference sources: the Google Analytics Help Center and Google Analytics developer documentation.