Setting up Google Analytics 4 (GA4) means creating a property and a web data stream, installing the Google tag on every page, marking the actions that matter as key events, and checking the data before relying on it. Universal Analytics stopped processing data on July 1, 2023, according to Google's help center, so a site that carries only old Universal Analytics tags is not being measured at all.
Last updated October 21, 2026. Data points below carry their own as-of dates.
What are the key takeaways on GA4 setup?
A working GA4 setup needs a live tag on every page, two or three key events tied to business goals, event data retention changed from the two-month default to 14 months, and a data check before anyone reports from it.
- Skipping key events leaves an account that shows traffic but not whether the traffic did anything valuable.
- Event data retention defaults to two months, so set it on day one.
- Test new events in DebugView before trusting them.
Quick definition: what is a key event?
A key event is an event in GA4 that a site owner marks as important to the business, such as a purchase or a form submission. It is the current term for what earlier GA4 material called a conversion.
What are the key dates and limits to know?
The key facts are three dates and two retention settings, all from Google or documented by a university analytics team. Knowing them prevents the two most common setup surprises: missing data from an old tag and losing history after two months.
| Fact | Detail | Source and as-of date |
|---|---|---|
| Universal Analytics stopped processing data | July 1, 2023, for standard properties | Google Analytics Help, page last updated July 16, 2025 |
| Universal Analytics access ended | The week of July 1, 2024, when properties, the application programming interface and data became unavailable | Same Google Analytics Help page |
| GA4 setup steps in Google's guidance | Six for everyone and five more for advertisers | Google Analytics Help |
| Default event data retention | Two months | NC State University Communications |
| Maximum event data retention | 14 months | Same NC State page |
Retention rules can change, so confirm the current options under Admin, then Data Settings, then Data Retention in your own property.
What are the steps to set up Google Analytics 4?
GA4 setup has six steps, and Google's own setup guidance lists them in this order: create the property and data stream, collect website data, turn on Google signals, set up key events, add users, and link Google Ads if the business advertises.
| Step | What to do | How to check it worked |
|---|---|---|
| 1. Create the property and data stream | Add a GA4 property for the site or app, then add a web data stream | A measurement ID appears for the stream |
| 2. Install the Google tag | Place the tag on every page directly or through Google Tag Manager | The real-time report shows your own visit |
| 3. Turn on Google signals | Enable the setting for cross-device and audience reporting where the privacy policy allows | The setting shows as active in the property |
| 4. Set key events | Mark the actions that matter, such as a purchase, a form submission or a demo request | Each key event appears in reports after a test |
| 5. Set data retention | Change event data retention from two months to the 14-month maximum | Data Retention shows 14 months |
| 6. Add users | Give the right people Editor access and limit Admin access | The user list matches who needs access |
To keep data beyond 14 months, export it or link GA4 to BigQuery.
How do you install the Google tag on a website?
You install the Google tag by creating a web data stream in the GA4 property, which generates a snippet of JavaScript, and placing that snippet on every page of the site. A business that already manages several tracking scripts can deploy the same tag through Google Tag Manager instead.
Check that the tag fires on the pages that matter, not only the home page, and confirm no old Universal Analytics code is the only tag left on the site.
How do you set up key events and goals in GA4?
GA4 tracks activity as events, and the events that matter to the business are marked as key events, the term GA4 uses for what Universal Analytics called goals. Choose them from what the site is for.
| Site type | Key events worth tracking |
|---|---|
| E-commerce | Completed purchase or checkout |
| Publisher | Newsletter signup or gated content download |
| Service business | Contact form submission or demo request |
| Any site | A specific page reached, such as pricing or booking confirmation |
Keep the list short, so each key event answers a business question.
What do GA4 audience reports show?
GA4's user reports show who visits a site, including age range, location, device type and interest categories, alongside engagement measures such as average engagement time. They sit under the Reports section, not in a single Audience tab, which trips up marketers who learned Universal Analytics.
The useful work happens when dimensions are compared. A business might find that visitors from one region convert on mobile at a different rate than desktop visitors from the same region.
What should you check before trusting the data?
Run a data check before making any decision from a new GA4 account, because a quiet error such as an event that was never configured to fire shows zero data with no warning.
- Filter out internal traffic so employee visits do not inflate numbers.
- Configure cross-domain tracking if the business operates more than one domain.
- Use DebugView, GA4's real-time testing tool, to confirm new events fire correctly.
- Review user permissions so the right people can edit and few have Admin access.
- Compare a week of GA4 numbers with another source, such as ad platform or sales data, to catch large gaps.
How do you turn GA4 data into marketing decisions?
You turn GA4 data into decisions by opening the Acquisition report to see which channels bring traffic and which bring traffic that converts. A channel with high volume and low conversion is not automatically a bad channel, but it needs a different follow-up message than a channel that already converts well.
Document the decisions in the communications plan, pair channel data with the guide to measuring PR effectiveness, and review the whole channel mix with the digital marketing audit guide. The PR and marketing strategy service connects analytics to campaign results.
Frequently asked questions
Is Universal Analytics still collecting data?
No. Standard Universal Analytics properties stopped processing data on July 1, 2023, and Google ended access to Universal Analytics properties and data in 2024.
What is the difference between a conversion and a key event?
Key event is GA4's current term for an event marked as important to the business, and it is what earlier GA4 material called a conversion.
How long does GA4 keep data?
Event data retention defaults to two months and can be set to a maximum of 14 months, so set it when the property is created.
What is the most common GA4 setup mistake?
The most common mistake is skipping key events, which leaves an account able to show traffic but not whether it did anything valuable.
What should a team do first?
A team should confirm the GA4 tag fires on every page, mark two or three key events, set retention to 14 months, and run the data check above before anyone reports from the property.
