Google Analytics for beginners: the complete GA4 guide

This Google Analytics for beginners guide walks through Google Analytics 4 (GA4), from account creation through the reports that actually drive decisions. 

We’ll cover setup, verification, conversions (now called key events), Google Search Console and Google Ads linking, and user management. 

Here’s the catch: GA4 will technically work after a five-minute install, but the reports won’t actually help you make decisions unless you’ve configured it properly. Most beginners install GA4, look at the homepage dashboard, and never get real value out of it. 

The setup choices, not the install itself, are what makes the data useful. By the end of this guide, you’ll have GA4 installed, connected, and actually pointed at the data that matters for your business.

What is Google Analytics?

Google Analytics is a free web analytics tool from Google that tells you where your website or app visitors come from and what they do once they arrive. It’s the most widely used analytics platform on the web, by a large margin.

The current version is Google Analytics 4 (GA4). It replaced Universal Analytics (UA), which stopped collecting data in standard accounts on July 1, 2023.

Out of the box, GA4 can tell you:

• How many people visit your site
• Where they came from (organic search, paid ads, social, direct, and more)
• What pages they viewed
• What they did on those pages
• Whether they completed actions you care about

That list looks similar to every other analytics tool, and it is. The difference, and the reason this guide exists, is that GA4 will only show you what you configure it to. 

A default install captures generic page views and a handful of automatic events. To get the data that drives real decisions, you have to decide what to track and how to connect GA4 to the rest of your marketing stack.

The rest of this guide helps you make those choices, in order.

What is Google Analytics used for?

Google Analytics is used to make better marketing decisions by showing what’s working on your website and what isn’t. Five of the most common use cases for marketers:

1. Finding your best traffic sources. GA4 shows you how much traffic each channel brings (organic search, paid search, social, email, referral, direct) and how that traffic behaves once it arrives. If organic search drives most of your revenue, you know where to put more effort. If a paid campaign is bringing volume but no conversions, you know where to cut.
2. Spotting your best (and worst) pages. GA4 reports rank every page by views, engagement, and conversions. Use this to find the pages doing the heaviest lifting so you can build more like them, and to find pages getting traffic but losing visitors so you can fix or replace them.
3. Tracking whether conversions are growing. GA4 lets you mark specific events as key events (the new name for conversions) and see how many people complete them. Track them over time and you’ll know whether your changes are working. Compare them by source and you’ll know which channels deserve more budget.
4. Understanding who your audience actually is. GA4 reports show user location, language, and interests, plus the devices and browsers they use. Pair that with the pages they engage with and you have a clearer picture of your real buyer, useful for ad targeting, content planning, and product positioning.
5. Catching problems early. A page that suddenly stops getting traffic. A checkout funnel where 90% of users drop on step two. A campaign pushing the wrong audience to the wrong page. GA4’s Realtime and standard reports surface this kind of thing before it becomes a quarter of lost revenue. But only if you check.

Each of these depends on setup. The reports are only as useful as the configuration behind them.

How does Google Analytics work?

Google Analytics works by collecting every meaningful interaction on your site or app, storing those interactions as data, and turning them into reports you can analyze.

The unit of data in GA4 is an event. Almost everything a visitor does is captured as an event: page views, clicks, scrolls, file downloads, video plays, purchases. Each event can carry parameters that describe it (which page was viewed, which file was downloaded, which product was purchased).

Events get to GA4 through a small piece of tracking code installed on your site. That code can be added manually, through a plugin, or via Google Tag Manager (GTM). We’ll cover all three in the setup section.

Once GA4 starts collecting, it processes the data and makes it available in standard reports (Acquisition, Engagement, Retention, Key Events, Realtime) and in custom analyses you build yourself.

Deeper definitions for events, parameters, key events, and the rest come later in this guide.

How to set up Google Analytics

To set up Google Analytics, you’ll create a Google Analytics account and a GA4 property, install tracking code on your site, verify data is flowing, then connect the integrations that turn raw event data into useful reports.

The full sequence:

1. Define what to track and who needs access
2. Create a Google Analytics account and property
3. Install GA4 on your website
4. Verify your setup is working
5. Set up conversions (key events)
6. Connect GA4 to Google Search Console
7. Link GA4 to Google Ads
8. Add users and manage access

Each step below is a switch that turns on a specific report or decision later in this guide.

3 questions to answer before setting up GA4

Before setting up GA4, think about what business actions matter, what channels you invest in, and who needs access to the data. These three answers shape almost every setup decision below and may be the most important 10 minutes you spend on the entire process.

In the words of Sergei Rogulin, Head of Organic & AI Visibility at Semrush:

“The most common mistake, I believe, is treating GA4 like a plug-and-play reporting tool instead of defining the measurement logic first. Beginners often start tracking events without a clear naming structure or conversion hierarchy, resulting in low trust in the data: messy reports, broken attribution, duplicated events. You need to invest quite a lot of time setting it up properly, because GA4 is not an out-of-the-box solution. It is a constructor you need to adjust for your needs.”

The three questions:

1. What business actions matter? Write down two to four specific things a visitor can do on your site that are worth money or close to it: form submissions, purchases, sign-ups, demo bookings, paid subscriptions. These become your key events when you get to the conversions section below.
2. What channels are you already investing in? List the marketing channels actively driving people to your site: organic search, paid ads, social, email, referrals, etc. These determine which integrations matter most when you get to the Google Search Console and Google Ads sections.
3. Who needs access to the data? List the people who’ll look at or change GA4: you, an agency, a developer, a contractor, a marketing manager. Each needs the right role when you get to the users and access management section.

Keep these answers in mind as you walk through the setup steps below.

How to create a Google Analytics account

To create a Google Analytics account, go to analytics.google.com and sign in with the Google account that will own the data. You’ll come out of this step with a Measurement ID, which every other step depends on.

To get there, you’ll set up three things: 

1. The account is the top-level container that usually represents your company
2. A property is the specific website or app you want to measure (one account can hold multiple properties) 
3. A data stream is the source of data flowing into a property (for a website, you’ll create one web data stream)

After signing in, click “Start measuring.” Give your account a name (your company name works) and set the data sharing preferences. Click “Next.” Name your property (your website name works) and set the reporting time zone and currency. 

Time zone matters because every report defaults to it. Currency matters if you’ll track revenue.

Next, choose your industry category, business size, and primary business objectives. The objectives you pick (for example, “generate leads” or “drive online sales”) determine which reports get pre-loaded. If you’re not sure, choose “Get baseline reports.” You can change reports later. 

Accept the terms of service, then select “Web” as the platform, enter your website URL, and give the stream a recognizable name. 

Leave Enhanced measurement turned on. That toggle automatically tracks scrolls, outbound clicks, site search, video engagement, form interactions, and file downloads without any extra code (page views are tracked by default outside of this toggle).

Once the stream is created, GA4 generates a Measurement ID in the format G-XXXXXXXXXX. Copy it. You’ll need it in the next step.

How to install GA4 on your website

To install GA4 on your website, you need to add a small piece of tracking code to every page so events can flow to your Measurement ID. There are three ways to do it. Pick the one that matches the tools you already use.

Here’s how each one works:

• Google Tag Manager: Google Tag Manager is a free tool that lets you install tracking tags without editing your site’s code. In GTM, create a new tag, choose Google tag as the tag type, paste your Measurement ID into the Tag ID field, set the trigger to All Pages, save, and publish the container.
• WordPress plugin: If you’re wondering how to add Google Analytics to WordPress without writing code, a plugin like Site Kit by Google installs the tracking code site-wide without touching theme files. Install the plugin from the WordPress plugin directory, activate it, connect it to your GA account when prompted, and select the property you want to track.
• Manual code snippet: This is the most direct method and gives you the most control. In GA4, go to Admin > Data Streams > [your stream] > Google Tag > View tag instructions > Install manually. Copy the gtag snippet, paste it as high in the <head> of every page as possible, and deploy.

Whichever method you choose, the goal is the same: The tag fires on every page load and sends events to your Measurement ID. The next step verifies that it actually is.

How to verify your GA4 setup is working

To verify your GA4 setup is working, open the Realtime overview report in GA4, then visit your site in another tab. If the tag is firing, you’ll see your visit appear inside 30 seconds. This is the fastest way to confirm data is flowing before you trust the rest of your reports.

In GA4, click Reports in the left navigation, then Realtime overview. You’ll see a card showing Active users in last 30 minutes, plus cards for active users in last 5 minutes, active users per minute, traffic source, audience, and a live location map.

To trigger the report, open your website in a new browser tab. Within about 30 seconds, the user count should tick up by one and your current page should appear in the Views by Page title and screen name card.

If nothing shows up after a minute or two, the tag isn’t firing on the page you opened. Most often this is one of three things: 

1. The tag wasn’t deployed everywhere (check your install method)
2. The page is blocked by a consent banner that hasn’t been accepted
3. You’re running an ad blocker that’s blocking GA4 in your own browser (try a different browser without extensions, or use a private window)

For deeper troubleshooting, use DebugView. It shows every event, parameter, and user property as it arrives, in real time. To turn debug mode on for a session, open Google Tag Assistant and connect it to your site (Tag Assistant turns on debug mode automatically), or set ‘debug_mode’: true in your gtag configuration. Then in GA4, go to Admin > Data display > DebugView.

DebugView is where you confirm specific events fire correctly (a form submission, a file download, a video play). Use it any time you set up a new event in this guide and need to confirm it’s working before relying on it.

How to filter out your own traffic in GA4

To filter out your own traffic in GA4, define an internal traffic rule on your web stream (so GA4 knows which IPs to flag as internal), then activate the matching data filter (so GA4 actually excludes that traffic from reports). Without this, every time you, a developer, or a tester visits your own site, the visit counts as real traffic and skews your reports.

Most beginners don’t realize they’re polluting their own data. Even modest quality assurance work, a designer reviewing a layout, or a developer testing a form can add 30 or 40 self-visits a week to a low-traffic site, which is enough to make your engagement metrics and conversion rates lie to you.

Here’s how to filter out your own traffic in GA4:

1. (Optional) Find your public IP address by searching “what’s my IP” in Google. You can also click “What’s my IP address?” inside the form in step 4.
2. In GA4, go to Admin > Data streams > [your stream] > Configure tag settings
3. Click Show more to reveal advanced options, then click Define internal traffic
4. Click Create. Give the rule a name (anything, e.g., “My home office”). Leave traffic_type value as internal. Under IP addresses, leave the match type as IP address is in range (CIDR notation), and enter your IP or your office network’s CIDR range. Click Create.
5. Go back to Admin > Data collection and modification > Data filters. You’ll see a filter named Internal Traffic in Testing state by default, with operation set to Exclude
6. Click the filter, change the state to Active, and save

The filter now excludes any session tagged as internal traffic from your standard reports. Add additional IPs (your home network, your agency, your developer) as you go.

How to set up conversions (key events) in GA4

To set up conversions in GA4, mark the events you want to count as “key events” so GA4 measures, reports on, and (later) syncs them to other tools as goal completions. Without this step, every event GA4 collects looks the same as every other event, and you have no way to see which actions on your site actually matter.

A key event is any event you’ve designated as a meaningful action: a form submission, a file download, a purchase, a sign-up. GA4 still collects everything as a generic event by default. Marking something as a key event tells GA4 to track it as a goal, surface it in the Key Events report, and (once you link Google Ads later in this guide) treat it as a conversion action you can optimize against.

The simplest way to mark an event as a key event:

1. In GA4, go to Admin > Data display > Events.
2. The page opens on the Key events tab (which lists events you’ve already marked). Switch to the Recent events tab to see all events GA4 has collected from your site in the last 28 days.
3. Click the star icon in the Mark as key event column next to the event you want to mark (for example, “file_download” for tracking PDF downloads, or “purchase” if you’ve configured ecommerce).

The event now appears on the Key events tab as a configured key event. From this point on, GA4 counts it toward conversion totals across your reports, and you can compare conversion volume across traffic sources, landing pages, and campaigns.

If you want to track an event GA4 isn’t already collecting (like a click on a specific button), you’ll need to configure it through Enhanced Measurement, create a custom event in GA4, or build a tag for it in Google Tag Manager. That’s beyond the scope of this beginner guide, but the Semrush GA4 reporting guide walks through it.

How to connect GA4 to Google Search Console

To connect GA4 to Google Search Console (GSC), link the two products in GA4’s Admin and then publish the Search Console collection to your Reports navigation. Without this connection, GA4 can tell you your traffic came from organic search, but it can’t tell you which queries drove it. With the connection in place, you get query-level attribution: the actual searches that brought users to specific landing pages.

This is the integration most beginner Google Analytics tutorials skip, and it’s the one that makes GA4 actually useful for SEO. If you care about which queries are sending traffic and which landing pages those queries land on, this is the step that unlocks it.

Prerequisite: You need to be a verified property owner in GSC for the site you’re linking, and an Editor (or higher) in the GA4 property.

Here’s how to make the link:

1. In GA4, go to Admin > Product links > Search Console links and click “Link”
2. Click “Choose accounts” and pick the GSC property that matches your site. Click “Confirm”
3. Click “Next,” then Select the web data stream you want to attach Search Console data to. Click “Next,” then “Submit.”

The link is made, but the reports aren’t visible yet. One more step:

1. Go to Reports > Library
2. Find the Search Console collection card, click the three-dot menu on the card, and click “Publish”

Now you’ll see a Search Console entry in the left navigation under Reports. Click into it and you’ll find two reports: Google organic search queries (which searches sent traffic) and Google organic search traffic (which landing pages got that traffic).

Use Queries to find the specific searches your pages already rank for, then use the landing pages report to see which content is doing the work. This is the foundation of any Google Analytics SEO report, and it’s the data you’ll come back to when planning content and tracking SEO performance over time.

How to link GA4 to Google Ads

To link GA4 to Google Ads, go to Admin > Product links > Google Ads links in GA4 and connect the Google Ads account running your campaigns. This link unlocks three things in one move: 

1. The key events you’ve already configured in GA4 become conversion actions in Google Ads, so you can use them to optimize bidding 
2. Google Ads campaign data appears inside GA4’s acquisition reports, so you can compare paid performance against organic and other channels
3. Audiences you build in GA4 (visitors who viewed a product page, users who started checkout) become available in Google Ads for remarketing

Without the link, you’d be configuring conversions twice (once in GA4 for analytics, once in Google Ads for ad bidding), and Google Ads wouldn’t see GA4’s audience definitions at all.

Prerequisite: You need to be an Administrator (or have manage access) in the Google Ads account you’re linking, and an Editor in the GA4 property.

Here’s how to make the link:

1. In GA4, go to Admin > Product links > Google Ads links and click “Link”
2. Click “Choose Google Ads accounts,” pick the account (or accounts) you want to link, and click “Confirm”
3. Click “Next,” then turn on Enable Personalized Advertising if you want GA4 audiences to be available in Google Ads remarketing. Click “Next.”
4. Click “Submit”

Once the link processes, you’ll see a new Google Ads section appear in GA4’s Acquisition reports (showing your paid campaigns alongside your organic traffic), and your GA4 key events will show up as conversion options inside Google Ads when you configure bidding.

How to add users and manage access in GA4

To add users and manage access in GA4, go to Admin > Account access management (for account-level access) or Property access management (for access to a single property), then add the email addresses of the people who should see your data. 

Most marketers need to add an agency, a colleague, or a developer within the first week of setup, and getting the role right keeps the wrong people from accidentally changing the wrong things.

GA4 has five role levels, ordered from least access to most:

To add someone:

1. In GA4, go to Admin, then Account access management or Property access management (depending on the level of access you want to grant)
2. Click the blue “+” button in the top right and choose Add users
3. Enter the person’s email address, choose the role from the dropdown, and click “Add”

The person will receive an email invitation. They sign in with their Google account and the property appears in their GA4.

Want a deeper look at GA4 roles and what each one can do across account and property scope? The Semrush guide to GA4 user roles walks through it.

Do you need Google Consent Mode for EU traffic?

If you have EU traffic, you need Google Consent Mode v2 in addition to the GA4 setup above. Consent Mode v2 sends consent signals from your cookie banner to GA4 (and other Google tags) so GA4 can adjust what it tracks based on what each user agreed to.

Without it, EU sessions either don’t get measured at all (depending on your consent management platform) or get measured in ways that put you out of compliance with GDPR. Either outcome makes your EU data unreliable.

Consent Mode is a separate setup task that lives outside the scope of this beginner guide. Most consent management platforms (Cookiebot, OneTrust, Termly) ship a GA4-compatible Consent Mode integration: activate it on the CMP side, then verify in GA4’s Realtime report that consent signals are arriving. Google’s consent mode setup guide walks through the technical details.

8 key GA4 concepts every marketer should know

Every marketer should know eight core GA4 concepts: events, parameters, properties and data streams, key events, users vs. sessions, dimensions vs. metrics, attribution, and audiences. 

These are the GA4 basics every report assumes you already understand. Get them clear and the rest of the platform stops feeling foreign. Let’s break them down.

1. Events

An event in GA4 is any user interaction GA4 records, including page views, clicks, scrolls, file downloads, video plays, purchases, and any custom action you’ve configured. Everything GA4 measures is stored as an event.

2. Parameters

A parameter in GA4 is a piece of data attached to an event that describes the context of that event. For a page_view event, parameters include the page title, page location, and page referrer. For a purchase event, parameters include transaction ID, value, and currency.

3. Properties and data streams

A property is the container GA4 uses to collect data for a specific website or app, and a data stream is the source of data flowing into that property. One account can hold multiple properties (one per site or app), and one property can have multiple data streams (one for your website, one for an iOS app, one for an Android app, all reporting into the same property).

4. Key events

A key event in GA4 is any event you’ve marked as a meaningful goal, such as a form submission, a purchase, or a sign-up, so GA4 tracks it as a conversion. Key events replaced the term “conversions” in March 2024.

5. Users vs. sessions

A user in GA4 is one unique visitor to your site, identified by a cookie or signed-in Google account, while a session is one distinct visit by that user that ends after 30 minutes of inactivity. One user can have many sessions, and one session can contain many events.

6. Dimensions vs. metrics

A dimension is a descriptive attribute (page title, country, device category, traffic source); a metric is a number (users, sessions, conversions, revenue). Reports combine the two: rows show dimensions, columns show metrics. In the report above, “Session primary channel group” is the dimension; “Users,” “Sessions,” and “Engagement rate” are metrics.

7. Attribution

Attribution in GA4 is the rule GA4 uses to decide which marketing channel gets credit for a conversion when a user interacted with more than one. GA4’s default attribution model is data-driven, meaning Google’s machine learning assigns fractional credit across channels based on what actually influenced the conversion.

8. Audiences

An audience in GA4 is a group of users who share a specific behavior or attribute, like “visitors who viewed a product page but didn’t purchase” or “users from Canada.” You build audiences in GA4 and use them in reports or push them to Google Ads for remarketing.

The GA4 reports marketers actually need

The GA4 reports marketers actually use day to day are Acquisition, Engagement, Retention, Realtime overview, and Realtime pages. Each answers a different question and lives in a predictable place in the left navigation.

Key events don’t have a standalone report in GA4’s left navigation. Once you’ve marked an event as a key event (covered in the setup section), key event counts show up as a column inside the Acquisition and Engagement reports, and a summary appears on the Reports snapshot at the top of the Reports nav. That’s where you compare conversions by channel, by source, and by landing page.

These reports together answer almost every basic GA4 question, and they’re where every marketing decision we cover later in this guide ultimately comes from. The Explore section, covered next, is where you build custom analyses GA4’s standard reports can’t show you out of the box.

How to use the Explore section in GA4

To use the Explore section in GA4, click Explore in the left navigation rail, pick a template from the gallery, and configure the variables on the left to slice your data the way standard reports can’t. Explore is where you build the custom views GA4’s standard reports don’t show out of the box, and where most of GA4’s flexibility actually lives.

There are six templates in the Explore gallery, but most marketers only need three:

• Funnel exploration: Build a step-by-step funnel from any sequence of events (e.g., viewed product → added to cart → started checkout → completed purchase) and see where users drop off at each step
• Path exploration: See where users go before and after any page or event on your site. Useful for finding which pages send the most users to your conversion pages, or which pages users land on before bouncing.
• Free form: A drag-and-drop interface that lets you build a custom report by adding any combination of dimensions, metrics, and segments. Use it when no other template fits.

The other three templates (Segment overlap, Cohort exploration, User lifetime) exist for more advanced segmentation and lifetime-value analysis. You can come back to them once the three above feel natural.

Each exploration you build is saved to your property and can be shared with anyone who has access to it.

How to use annotations in GA4

To use GA4 annotations, open any standard report, click the View annotations icon (a small speech-bubble icon) in the report toolbar at the top, then click Create annotation in the panel that opens on the right. The note you save will appear on every report covering that date.

Annotations let you mark when something significant happened (a redesign, a campaign launch, a Google update, a site outage) so you remember it later when you’re trying to explain a spike or drop in the data.

To add one:

1. In GA4, open any standard report (for example, Reports > Life cycle > Acquisition > Traffic acquisition)
2. Click the “View annotations” icon in the report toolbar at the top. An Annotations Viewer panel slides in from the right.
3. Click “Create annotation” at the bottom of the panel
4. Select the date the annotation applies to (or a date range for events that span multiple days)
5. Type a short description, choose a color, and click “Save”

The annotation appears as a small marker on the chart for any report covering that date, visible to anyone with access to that property.

What to do with your GA4 data

GA4 is only useful if the data drives a decision. The five reports below answer the five marketing decisions you’ll keep coming back to: where to invest, which content to expand, which campaigns are working, whether your audience is returning, and what to optimize next.

Use Acquisition to decide where to put your marketing budget

Channels that bring traffic AND key events are the ones to scale. Open Reports > Life cycle > Acquisition > Traffic acquisition, sort by Users to see volume and by Key events to see actual conversions. 

If a channel brings traffic but no key events, the audience is wrong, the landing pages don’t convert, or both. If it barely brings traffic but converts every visit, that’s a sign to scale it.

Use Engagement to decide which content to expand

Your best pages do two things: they engage users and they drive conversions. Open Reports > Life cycle > Engagement > Pages and screens to see views, engagement time, and key events per page. 

The pages at the top of both columns are your top performers; build more like them. The pages with traffic but low engagement are leaking visitors; revisit the content, the layout, and the offer.

Use key events to decide which campaigns are working

Key event data appears as a column inside both Acquisition and Engagement reports. In the Traffic acquisition report, add Session campaign as a secondary dimension to see how many key events each campaign delivered. 

The campaigns at the top of that list are working. The campaigns near the bottom either need creative changes, a different audience, or to be paused.To pick between the three, look at where the campaign is breaking down. 

• High impressions but low clicks means the creative isn’t pulling people in (rewrite the headline or copy or swap the visual)
• Decent clicks but no conversions means the audience or the landing page is off (change targeting, adjust the offer or rebuild the page)
• Low impressions and low clicks means the spend or targeting isn’t reaching anyone (pause and rethink before adding budget)

Check out our full guide to paid advertising for more info on running great ads.

Use Retention to decide whether you need a re-engagement strategy

Open Reports > Life cycle > Retention to see how many users come back after their first visit.

If your retention curve drops steeply after day one and doesn’t recover, you have an acquisition-quality or first-time-experience problem. If you maintain a healthy returning-user base, you can invest more in audience expansion. If the curve is flat at zero, your tracking is probably misconfigured. 

Always verify in DebugView before changing your strategy.

Use Google organic search queries to decide what to optimize

Open Reports > Search Console > Queries to see which queries drive organic traffic and to which landing pages. The biggest opportunity is queries ranking in top 10 positions with high impressions and zero clicks; those are the closest to a click-through breakthrough with the right on-page work. 

This is how to use Google Analytics for SEO at scale: pair this with the Google organic search traffic report to see which landing pages are doing the work, then run those pages through Semrush’s Site Audit tool to catch technical or on-page issues that could be holding them back.

Bring it together with Organic Traffic Insights

Organic Traffic Insights is a Semrush tool that pulls GA4, GSC, and Semrush’s keyword database into a single dashboard so you can make informed SEO and SEM decisions based on real data. 

Once you’ve connected your GA4 property and your GSC account, you can see which keywords drove traffic to which landing pages (including the “not provided” queries GSC normally hides), what those pages currently rank for, and which of them are converting in GA4. 

Every step in this guide has been a switch that turns on one of these decisions. 

• The Measurement ID let you collect data
• The install code put events into GA4
• Key events told GA4 what counted
• GSC linking surfaced the queries
• Google Ads linking unlocked conversion attribution and audiences

Each one was a setup decision that determined what GA4 could later tell you. That’s the point; GA4 is only useful if it’s set up to answer the right questions.

GA4 limitations marketers should know

GA4 has four well-known limitations every marketer hits at some point. None of them are reasons to distrust the platform; they’re constraints to manage and settings to adjust.

Data sampling on high-volume properties

GA4 samples data when a query exceeds 10 million events in the date range. Sampled reports use a representative subset of your data instead of all of it, which is faster but can produce small numerical differences across refreshes. 

If you see a “This report is based on sampled data” indicator, take the numbers as estimates, not exact counts. To work with unsampled data on high-volume queries, you’ll need GA4 360 (the paid version) or to export raw event data to BigQuery.

Data retention defaults

GA4 retains event-level data for two months by default. Most marketers want longer. 

To change it to the maximum 14 months, go to Admin > Data collection and modification > Data retention and switch the Event data retention dropdown to 14 months. 

Do this on day one of setup, because the change doesn’t apply retroactively, and any data older than the current setting is permanently dropped. (User data retention has its own dropdown on the same page and is already set higher by default.)

“(not set)” values in reports

GA4 shows “(not set)” in a dimension column when it received an event but couldn’t capture the relevant parameter. Common causes: a page view fired before the page title finished loading, a custom dimension wasn’t configured, or a parameter wasn’t sent with an event. 

“(not set)” rows aren’t errors and don’t mean your data is broken. They mean a specific parameter is missing for those rows, and the events themselves are still counted.

The 24-hour lag on standard reports

Standard GA4 reports update on a 24- to 48-hour delay. If you mark a new key event today, you’ll see it in the Key events configuration immediately but not in standard reports until the next processing window. 

Use the Realtime report for instant feedback during testing, and use DebugView when you need event-level verification within seconds. For day-to-day analysis, compare week-over-week and month-over-month rather than checking yesterday’s numbers today.

Your GA4 is set up. Now what?

Once GA4 is set up, your next job is to look at the right data on the right cadence. The five reports above answer the five decisions you’ll keep making: where to invest, which content to expand, which campaigns are working, whether your audience is returning, and what to optimize next. Treat them as your weekly check-in.

If you want one place that combines GA4 with the keyword data you need to act on it, try Organic Traffic Insights. It pulls your GA4 traffic, GSC queries, and Semrush rank data into one view so you can spot the pages worth optimizing at a glance.