Google Analytics 4 (GA4) is Google's free web and app analytics tool. It shows you who visits your site, where they come from, how long they stay on each page, and whether they ultimately fill out a form or make a purchase. All you need to set it up is a Google account, access to your website, and about half an hour. Below, I explain both how GA4 works and how to set it up step by step.

What Is Google Analytics 4 and What Does It Do?

I describe GA4 in the simplest possible way: it is the black box of your website. Everything a user does from the moment they enter the site until they leave, including clicks, scrolls, video views, form submissions, and purchases, is recorded here. By looking at these records, you can see which channel generates revenue and which one merely consumes your budget.

I have been doing this work for more than ten years, and I still encounter the same situation most often: businesses spending serious money on advertising without knowing what those ads actually deliver. Last year, a furniture company we worked with was allocating half of its monthly budget to Instagram. Once we configured GA4 properly, we discovered that most of its sales were coming from Google searches. The budget was redistributed, and within three months the impact on revenue was clearly noticeable.

The real power of GA4 is that it allows you to base your decisions on data rather than assumptions. Which product page attracts attention but does not sell, why mobile users get stuck in the cart, which blog post sends traffic to the contact form... The answers to all these questions are somewhere in GA4.

There is one more thing to remember: GA4 is now Google's only standard analytics tool. The previous version, Universal Analytics, stopped processing data on July 1, 2023. In other words, saying "we had an old dashboard, we still check it there" is no longer meaningful.

Differences Between GA4 and the Old Universal Analytics

People who used the old system usually have the same reaction when they first open GA4: "Where did everything go?" That confusion is normal because it is not only the interface that has changed, but the entire logic behind how data is collected.

Universal Analytics was built around sessions and pageviews. GA4, on the other hand, treats everything as an "event." A pageview is an event, clicking a button is an event, and so is a purchase. This approach may seem abstract at first, but in practice it provides much more flexible measurement. You now decide exactly what you want to measure.

The second major difference is the "engagement rate," which replaced the bounce rate. In the old system, if a user entered a single page and then left, it was counted as a "bounce" even if they had spent five minutes reading that page. This was genuinely frustrating for blog owners. In GA4, sessions lasting more than 10 seconds, including at least two pageviews, or ending with a key event are considered engaged sessions. It is a much fairer measurement.

The third difference is the ability to track a website and mobile app under the same property. For an e-commerce brand with both a website and an app, being able to see the user's journey in one place was previously something that could generally only be achieved with paid tools.

How to Set Up Google Analytics 4 Step by Step

The setup is not as technical as it may seem. If you know where everything is on the screen, you can complete it in half an hour even on your first attempt. Follow these steps in order:

1. Create an account. Go to analytics.google.com with your Google account and click the "Start measuring" button. Entering your company name as the account name is sufficient.
2. Create a property. Enter your website name as the property name. Select "Türkiye" as the reporting time zone and "Turkish Lira" as the currency. Be careful: if you skip this step and continue with the default settings, orders received after midnight may be attributed to the following day.
3. Enter your business information. Select your industry and business size. Then choose the options that best match your needs on the business objectives screen; this selection determines which reports are displayed by default.
4. Add a data stream. Select "Web" as the platform, enter your website address, and give the stream a name. Make sure "Enhanced measurement" is enabled; this automatically tracks scrolling, outbound link clicks, and file downloads.
5. Get your measurement ID. Once the stream is created, you will see an ID starting with "G-" and an associated Google tag. This is the tracking code you will add to your website.
6. Add the code to your website. Choose one of the methods described in the next section and add the tag to all pages.
7. Verify the setup. Open your website from a different device and check the Realtime report in GA4. If you can see yourself there, the basic setup is complete.

Ways to Add the Tracking Code to Your Website

How you add the code to your website depends on the platform your site runs on. Making the wrong decision here can lead to data issues that take hours to fix later.

The most direct method is to paste the tag provided by Google immediately below the <head> section on every page of your website. This is perfectly sufficient for small corporate presentation websites. However, if you later want to add additional measurements such as advertising pixels, form tracking, or button clicks, you will need to involve a developer every time.

That is why I recommend Google Tag Manager for almost every project. You add the Tag Manager code to the website once, and from then on you manage all tags, including GA4, through the dashboard. Recently, one of our clients called on the morning of a campaign and asked, "Can we measure quote form submissions?" Because Tag Manager was already installed, we launched the tracking within fifteen minutes without involving the development team at all.

Things are even easier for those using ready-made platforms. WordPress has Google's official Site Kit plugin, while Shopify and many local e-commerce platforms offer a direct GA4 integration field. You simply paste your measurement ID into the relevant field. If your website was developed with custom software, planning the measurement infrastructure during the web design and development process from the beginning is much healthier than patching it in later.

One thing needs to be clear: do not use both methods at the same time. On websites where GA4 has been added both directly through the code and through Tag Manager, every visit is counted twice. If your engagement rate suddenly increases to a suspiciously high level, this is the first place you should check.

Settings You Must Configure After Installation

Just because the code is working does not mean the job is finished. In fact, this is where GA4 really starts to make a difference, and it is also the part most often overlooked. Configure the following settings on the first day of installation:

• Extend the data retention period. The default period is 2 months. Go to Admin > Data collection and modification > Data retention and increase it to 14 months. If you do not, you will not have the necessary data in Explorations when you want to compare performance with the same period from the previous year.
• Define your key events. Mark actions that are genuinely valuable to you, such as form submissions, purchases, and phone clicks, as "key events." Do not mark everything; if everything is important, nothing is important.
• Filter internal traffic. Define your office IP address so that your team's visits to the site throughout the day do not inflate the reports.
• Link your Google Ads account. This connection is essential if you want to see what users coming from ads do on your website and use GA4 audiences in advertising campaigns.
• Link Search Console. This allows you to see within GA4 which search queries bring visitors to your website and is extremely valuable for SEO monitoring.
• Configure cookie consent correctly. Under the KVKK, you need to obtain consent from users. Make sure your cookie consent tool is integrated with Google's Consent Mode; otherwise, you may face legal risks and lose advertising data.
• Define unwanted referrals. This is a critical setting for e-commerce websites using payment providers. If you do not configure it, users returning from a bank's payment page may be counted as a new session, making sales appear to have originated from the payment provider.

How Do You Test Whether the Setup Is Working Correctly?

It is easy to say, "We installed it, it works." The real question is whether it is working correctly. There are several practical ways to check this, and none of them requires technical expertise.

Your first checkpoint should be the Realtime report. Open your website on your phone, browse a few pages, and monitor your activity in this report. The page you visit and the city you are connecting from should appear within a few seconds. If nothing appears, the code is most likely either in the wrong place or not loading at all.

For more detailed testing, use the DebugView screen. When you open your website in debug mode using Google's Tag Assistant tool, you can see every triggered event second by second. If the relevant event does not appear when you submit a form, you can immediately identify where the problem is.

Finally, after a few days, review your data with common sense. Does your daily visitor count roughly match your server logs or advertising dashboards? Do not expect an exact match; there will be small differences because of users who reject cookie consent and those using ad blockers. But if one side shows 100 and the other shows 1,000, there is clearly a serious problem somewhere.

The First Reports You Should Check in GA4

Seeing dozens of reports and metrics when you first enter the dashboard can be overwhelming. My recommendation is to focus on only a few reports during the first month. The rest will come with time.

The Acquisition > Traffic acquisition report is the heart of the system. Here, you can see which channels visitors come from, such as organic search, paid advertising, social media, or direct traffic, and how many conversions each channel generates. Since May 2026, this report has also included a new channel called "AI Assistant." Clicks coming from AI assistants such as ChatGPT, Gemini, and Claude are now listed in a separate row. If you are curious about how visible your website is in AI-generated answers, start monitoring this row; if you are carrying out GEO activities, you can measure their impact here as well.

The Engagement > Pages and screens report shows which content receives attention. Pages with high traffic but a low engagement rate are generally pages where users cannot find what they are looking for. These pages are your first candidates for conversion rate optimization.

If you manage an e-commerce website, add the Monetization reports to your list as well. Seeing which products receive many views but few sales can tell you a great deal about pricing or product page structure. For more ideas on this topic, you can also read our article on increasing the conversion rate of an e-commerce website.

The Most Common GA4 Setup Mistakes

Over the years, we have encountered almost the same mistakes in hundreds of GA4 properties we have audited. They all have one thing in common: they are not noticed during setup but become apparent months later when an incorrect decision is made based on the data.

The most common mistake is not defining conversions at all. Website traffic is measured, but no one knows who filled out a form or who called. In such a case, GA4 only tells you "how many people came," which is one of the least important questions from a business perspective. What really matters is how many of those visitors became customers. If you want to calculate ROI in digital marketing, you cannot take a single step without this measurement.

The second common mistake is failing to tag campaign links. Traffic coming from an e-newsletter, WhatsApp message, or influencer post appears as "direct" or "referral" if UTM parameters are not added. While working with a cosmetics brand, the team was about to conclude that an influencer campaign had "generated no sales at all." Once the links were properly tagged, it turned out that the same campaign was actually the most profitable channel of the month.

The third mistake is failing to connect the advertising account. When GA4 and Google Ads do not communicate, the advertising system cannot learn which clicks actually turn into sales, and smart bidding strategies operate blindly. This is one of the first things we check in our Google Ads consulting processes.

In short, installing GA4 is the easy part. Turning it into a decision-making tool that genuinely makes money for your business requires the right settings and regular monitoring. If you would like support with this process, we can build your measurement infrastructure together as a digital marketing agency.

Frequently Asked Questions About Google Analytics 4

Is Google Analytics 4 paid?

No. The standard version of Google Analytics 4 is completely free and meets almost all the needs of small and medium-sized businesses. There is also a paid version called Analytics 360 for large organizations with very high data volumes.

How long does GA4 setup take, and when does the data appear?

The basic setup is usually completed within 15-30 minutes. If the code has been placed correctly, visits begin appearing in the Realtime report within a few minutes. Standard reports may take 24-48 hours to populate.

Can I transfer my old Universal Analytics data to GA4?

No. Universal Analytics stopped processing new data on July 1, 2023, and access to old properties was subsequently discontinued. Because the two systems use different data structures, historical data cannot be transferred to GA4. Your GA4 data history begins from the day you set it up.

Where should I add the GA4 tracking code on my website?

If you are adding the code directly, you should place it immediately below the <head> tag on every page of your website. If you use Google Tag Manager, you do not need to add the code separately to the website; simply configure the GA4 tag through Tag Manager. Using both methods at the same time causes data to be counted twice.

What does the engagement rate in GA4 mean?

The engagement rate shows the share of engaged sessions within total sessions. For a session to be considered engaged, it must last longer than 10 seconds, include at least two pageviews, or result in an action marked as a key event. It can be considered a more meaningful alternative to the old bounce rate.

Why does GA4 data not exactly match advertising dashboards?

There are several common reasons for this: users who reject cookie consent, ad blockers, different attribution models, and different measurement timings. Advertising platforms are based on their own clicks, while GA4 measures actual sessions on your website. Small differences are normal; if there are large discrepancies, the setup should be checked.

Is it necessary to connect GA4 to Google Ads and Search Console?

It is not mandatory, but it is strongly recommended. By connecting Google Ads, you can see what visitors coming from your ads do on your website and use audiences created in GA4 in your advertising campaigns. The Search Console connection allows you to see within GA4 which search queries bring users to your website.