Google Analytics 4 (GA4) is Google's current web and app analytics platform. It tracks what people do on your site after they arrive, from the pages they view to the forms they submit, and shows which channels bring in the visitors who actually take action.
If you've worked with the older Universal Analytics, GA4 can feel unfamiliar at first. The core idea is simple, though: everything is an event, and you decide which events matter most to your business.
What is Google Analytics 4?
Google describes GA4 as the next generation of Google Analytics, a property type that collects data from both websites and apps. Instead of organizing data around sessions and pageviews, it records every interaction as an event. A page view is an event. So is a scroll, a file download, or a purchase.
GA4 fully replaced Universal Analytics. According to Google, standard Universal Analytics properties stopped processing data on July 1, 2023, and 360 properties got a one-time extension that ended July 1, 2024. As of October 2026, GA4 is the only version of Google Analytics collecting new data.
Why GA4 matters for SEO and GEO
Search tools tell you about visibility. GA4 tells you whether that visibility turns into business. Ranking for a keyword or getting cited in an AI answer only pays off if visitors engage and convert, and GA4 is where you see that.
It's also becoming one of the main ways to measure traffic from AI tools. As of 2026, Google's channel definitions include an AI Assistant channel for visits referred by recognized AI assistants such as ChatGPT, Gemini, Copilot, and others. Google's documentation notes this channel excludes its own AI Overviews and AI Mode, which count as organic search. Some AI visits arrive without referrer data and still show up as Direct, so treat the number as a floor, not a total. Tracking this AI referral traffic alongside organic search gives you a fuller view of discovery.
How GA4 works
Events and parameters
Every interaction is logged as an event, and each event can carry parameters that add detail, such as the page URL or the value of a purchase. Some events are collected automatically, like page_view and session_start. Enhanced measurement adds common ones like scrolls and outbound clicks with a toggle. You can also send custom events for anything specific to your site.
Key events
Key events are the actions you care about most, such as a lead form submission or a booked demo. Google renamed "conversions" to key events in GA4 to align terms with Google Ads, where "conversion" now refers to actions used for ad bidding. You mark any event as a key event in the admin settings.
Engagement metrics
GA4 replaced bounce rate as the headline metric with engagement rate. A session counts as engaged if it lasts longer than 10 seconds, has a key event, or includes two or more page views. Bounce rate still exists, but it's now simply the share of sessions that weren't engaged.
Acquisition and attribution
GA4 sorts traffic into channels like Organic Search, Paid Search, Email, and Referral using a set of default rules. Those rules read your UTM parameters and referrer data, which is why consistent campaign tagging matters so much.
GA4 in practice
Imagine a B2B software company that publishes a series of comparison guides. In GA4, the marketing lead opens the Traffic acquisition report and filters to Organic Search. The guides drive plenty of sessions, but only a small share trigger the "demo_request" key event.
Digging into the landing page report, they see one guide converts far better than the rest. It has a clear call to action halfway down the page, while the others only link to the demo at the very bottom. The team tests adding mid-page calls to action to the other guides and watches the key event rate over the next month.
They also notice a steady stream of visits in the AI Assistant channel landing on the same guides. That tells them the content is being cited in AI answers, which shapes what they write next.
How to set up and use GA4 well
- Install the Google tag correctly. Add it to every page directly or through Google Tag Manager, then confirm data is flowing in the Realtime report.
- Turn on enhanced measurement. It captures scrolls, outbound clicks, site search, and file downloads without extra code.
- Define your key events. Pick two to five actions that tie directly to revenue or leads. Marking every event as a key event makes the data meaningless.
- Extend data retention. Standard properties default to a short retention window for exploration reports. Google lets you set it to 14 months. This doesn't affect standard reports, but it matters for deeper analysis.
- Link Search Console. The integration adds organic query and landing page reports, connecting what happened before the click with what happened after.
- Filter internal traffic. Exclude your own team's visits so they don't inflate engagement or key events.
- Tag campaigns consistently. Use lowercase UTM values and a shared naming guide so channel reports stay clean.
Common mistakes and misconceptions
Expecting it to match Universal Analytics. GA4 counts sessions and users differently, so year-over-year comparisons across the switch are rough at best.
Expecting it to match Search Console. Google Search Console counts clicks from Google results, while GA4 counts tracked sessions. Consent banners, ad blockers, and attribution differences mean they'll always differ.
Ignoring consent and privacy settings. In regions with consent requirements, users who decline tracking may be missing or modeled. Know how your consent setup affects your numbers.
Leaving key events undefined. Without them, GA4 shows traffic but can't tell you which traffic matters.
How Butter approaches GA4
At Butter, GA4 is how we connect search visibility to outcomes. Rankings and AI citations are leading signals, but we want to see whether they turn into engaged visits and key events. On our GEO+SEO plan, the Butter Analytics dashboard pulls in Google Analytics and Search Console, among 85+ integrations, so you can see organic search, AI referrals, and other channels side by side. We also use GA4 landing page data to decide which pages need on-page improvements first. We don't replace your analytics setup, but we help you read it in the context of your SEO and GEO work.
Frequently asked questions
Is Google Analytics 4 free?
Yes. The standard version of GA4 is free. Google also offers a paid enterprise version, Analytics 360, with higher limits and longer data retention options.
Can I still use Universal Analytics?
No. Standard Universal Analytics properties stopped processing data on July 1, 2023, and the 360 extension ended July 1, 2024. GA4 is the only version collecting new data.
Does GA4 track traffic from ChatGPT and other AI tools?
Partly. GA4's default channels include an AI Assistant channel for visits referred by recognized AI assistants. Visits that arrive without referrer information may still be counted as Direct.