Google Analytics 4, or GA4, replaced Universal Analytics in July 2023. If you opened your analytics one day and everything looked different, that's why. This guide explains what GA4 is, how it actually works, and what to do with it.
Quick answer
GA4 is Google's analytics tool for websites and apps. It tracks every action a user takes as an "event" — page views, clicks, form fills, video plays, scrolls. That's the big shift from the old Universal Analytics, which mostly tracked sessions and pageviews. Once you get your head around events, GA4 makes a lot more sense.
What changed between Universal Analytics and GA4
If you used Universal Analytics for years, GA4 feels weird. The reports look different, the metric names changed, and goals are gone. Here's the short version of what actually changed:
- Everything is an event. Pageviews are events. Clicks are events. Conversions are events. Universal Analytics had pageviews, sessions and events as separate things. GA4 simplified all of that.
- No bounce rate by default. GA4 uses "engagement rate" instead. Bounce rate did come back as an opt-in metric, but engagement rate is the new default.
- Cross-platform tracking. GA4 can track a user moving between your website and your app under one ID. Universal Analytics couldn't do that cleanly.
- Privacy-first. GA4 doesn't store IP addresses. It uses Google Signals and modelling instead of cookie-only tracking, which matters as third-party cookies disappear.
- Free BigQuery export. This used to be paid-only. Now even free GA4 accounts can pipe data into BigQuery for proper analysis.
How GA4 actually works
A user lands on your site. GA4 fires a `page_view` event automatically. They scroll, GA4 fires a `scroll` event. They click an outbound link, GA4 fires a `click` event. They submit a form, GA4 fires a `form_submit` event if you've set it up.
Each event carries a few parameters — page URL, device type, source/medium, and anything custom you've added. GA4 stitches these together to show you the user's journey.
You see this data in reports: how many users came, where they came from, what they did, how many converted.
The reports you'll actually use
GA4 has a lot of reports. Most of them you won't touch. These are the four that matter day-to-day:
- Reports → Acquisition → Traffic acquisition. Where your traffic comes from. Organic, paid, direct, referral, social.
- Reports → Engagement → Pages and screens. Which pages get visits and which actually engage people.
- Reports → Engagement → Events. Every event firing on your site, including conversions.
- Explore → Free-form. Build custom tables when the standard reports don't answer your question.
Setting up GA4 properly
If you just stuck the GA4 tag on your site and called it done, you're missing data. Here's the minimum proper setup:
1. Install via Google Tag Manager, not directly. It's easier to change later and works better with conversion tracking.
2. Mark your key actions as conversions. Form submissions, phone calls, purchases. Without this, GA4 can't tell you what's working.
3. Link Google Ads. This makes conversion data flow back so smart bidding can optimise properly.
4. Set up Google Signals if you want demographic data and cross-device tracking.
5. Filter internal traffic. Otherwise your team's site visits skew everything.
6. Set the right time zone and currency. This often gets missed and breaks reporting later.
What about GA4 for ecommerce?
GA4 handles ecommerce well, but it needs setup. Each step — view item, add to cart, begin checkout, purchase — needs its own event with the right parameters. If you're on Shopify or WooCommerce, plugins like the GA4 Shopify app or GTM4WP for WordPress handle most of this for you.
Without proper ecommerce events, you're flying blind. You'll see traffic but not revenue. Fix this first if you're an online store.
Common GA4 problems and what to do
My data doesn't match Universal Analytics. It won't, exactly. The metrics are calculated differently. Don't compare year-on-year using both — use GA4 to GA4 going forward.
My conversions stopped counting. Check that the event is still firing (use DebugView), check it's still marked as a conversion, check Google Ads is still linked.
I see weird traffic spikes. Often referrer spam or a bot. Set up referral exclusions and filter known internal IPs.
Real-time shows users but reports show zero. Reports take 24-48 hours to fully populate. Patience.
Is GA4 worth using?
Yes. It's free, it's the only Google option now, and once it's set up properly the reporting is genuinely useful. The learning curve is real if you came from Universal Analytics, but it's worth pushing through.
The businesses that get the most out of GA4 spend an hour setting it up properly, mark their real conversions, then check it weekly. That's it.
Frequently asked questions
What is GA4 in simple terms?
GA4 is Google's tool for tracking what people do on your website or app. It records every action as an event and shows you the results in reports. It replaced the older Universal Analytics in 2023.
Is GA4 free?
Yes. GA4 has a free version that covers what most small businesses need. A paid version (GA4 360) exists for enterprises with very high data volumes.
Is GA4 hard to learn?
It's harder than Universal Analytics was, but it's not impossible. Get the basics right (install, conversions, Ads link), and the rest you can pick up as you go.
Can I still use Universal Analytics?
No. Universal Analytics stopped collecting data in July 2023 for free accounts and July 2024 for 360 accounts. Historical data may still be accessible but no new data is being captured.
Do I need to set up GA4 even if I use Shopify analytics or another tool?
If you run Google Ads, yes. Google Ads needs GA4 conversion data to bid properly. If you don't run paid ads, you can get by with the tool you prefer, but GA4 is still the most useful free option.
