What is the Use of Google Analytics Code?

That little snippet of code from Google Analytics is the key to understanding everything about your website performance and the visitors who land there. Without it, you’re flying blind, relying on guesswork to figure out what’s working and what isn’t. This article breaks down exactly what that code is, what it does, how to use it, and why it's so fundamental for growing your business online.

What Exactly is the Google Analytics Code?

The Google Analytics code is a small piece of JavaScript, often called the “GA tag” or “tracking snippet,” that you install on your website. Think of it as an invisible ticket taker standing at the entrance of your site, quietly noting details about everyone who comes through without interrupting their experience.

There are two main parts you’ll hear about:

The Measurement ID (e.g., G-XXXXXXXXXX): This is your unique identifier for a specific set of data, known as a "data stream" in Google Analytics 4. It tells Google exactly which account and property to send the collected visitor data to.
The Global Site Tag (gtag.js): This is the full JavaScript snippet that contains your Measurement ID. This is the code that you actually install on your website pages. It handles all the work of collecting and sending the data back to Google’s servers.

Here’s what a typical GA4 Global Site Tag looks like:

You don't need to understand everything happening in this code. The most important thing to know is that this snippet is the bridge connecting your website to your powerful Google Analytics reports.

How Does the GA Tracking Code Work?

The process is incredibly fast and happens entirely behind the scenes in a matter of milliseconds. When someone visits a page on your site with the GA code installed, here’s the chain of events:

A person clicks a link and their web browser begins loading your webpage.
As the browser renders the page's HTML, it finds and executes the GA JavaScript snippet.
The script activates and immediately starts gathering anonymous information, such as the visitor’s device type, browser, screen resolution, and how they arrived on your site.
It then sets a small text file called a "cookie" on the user's browser. This cookie allows Google Analytics to recognize the person as a returning visitor if they come back later. (This is how GA differentiates between "Users" and "New Users".)
Finally, the script packages up all this information into a tiny "hit" (a small packet of data) and sends it over to Google's servers.
Google’s servers receive this hit, process it, and neatly organize the data into the reports you see in your Google Analytics account.

This happens for every single pageview, button click, or other interaction a visitor has on your website, giving you a rich, detailed story of how people engage with your content.

What Kind of Data Does It Collect?

The beauty of the GA code is the sheer volume and variety of insights it unlocks. Once installed, it starts populating reports that answer your most pressing questions about website performance. The data generally falls into four main categories:

Audience Data: Who are your visitors?

Demographics: Age and gender of your users (requires enabling Google Signals).
Geography: The country, state, and city your traffic is coming from.
Technology: The browsers, operating systems, and devices (desktop, mobile, or tablet) visitors use to access your site.

Acquisition Data: How did they find your website?

Traffic Channels: A breakdown of where your users come from, such as Organic Search (Google, Bing), Direct (typing your URL), Social (Facebook, Instagram), Referral (links from other websites), and Paid Search (Google Ads).
Source/Medium: A more granular look showing the specific source (e.g., google.com, facebook.com) and the medium (e.g., organic, cpc, referral).

Behavior Data: What do they do on your site?

Page Engagement: Which pages are they viewing most often and for how long?
Events: Specific actions users take, such as video plays, file downloads, link clicks, and form submissions. GA4 is built around an "event-based" model, meaning almost every interaction can be tracked as an event.
Landing Pages: The very first page a user lands on when they arrive at your site.

Conversion Data: Are they taking the actions you want?

Conversions: Crucial actions that you define as valuable. These are typically set up from existing events. Examples include a sale completion on an e-commerce site, a lead form submission, or a newsletter signup. This is the data that helps you measure your website's ROI.

How to Find and Install Your Google Analytics Code

Getting your GA tag is straightforward, and most modern website platforms make installation easy.

Finding Your Tracking Code in GA4

Log in to your Google Analytics account at analytics.google.com.
Click the Admin gear icon in the bottom-left corner.
In the "Property" column, select Data Streams.
Click on the Web data stream for your website. If you don't have one, you'll need to create it first.
Look for the section titled "View tag instructions". Clicking this will open a pane where you can see your Measurement ID (G-XXXXXXXXXX) and copy the full Global Site Tag (gtag.js) snippet.

Installing the Code on Your Website

There are two primary ways to get the code onto your site. For most people, the first option is the best.

Method 1: Using a Platform Integration or Plugin (The Easy Way)

Almost every major website builder and CMS has simplified this process. Instead of manually handling code, they just ask for your Measurement ID.

WordPress: Use a plugin like GA Google Analytics or Site Kit by Google. Go to the plugin's settings, find the field for the GA4 Measurement ID, and paste it in.
Shopify: Go to Online Store > Preferences. Find the Google Analytics section, paste your Measurement ID, and save.
Squarespace: Go to Website > Website Tools > External API Keys. In the Google Analytics field, paste your Measurement ID.
Wix: Navigate to Marketing & SEO > Marketing Integrations. Under Google Analytics, click "Connect" and follow the prompts to add your ID.

Method 2: Manual Installation

If you have a custom-coded website or your platform doesn't have an integration, you'll need to add the code manually. It sounds technical, but it’s really just a copy-and-paste job.

Copy the entire gtag.js code snippet from your Data Stream settings.
Access the source code for your website's pages.
Paste the entire snippet right after the opening tag on every single page of your website you want to track. If you use a template or "header" file, you can often just paste it there once, and it will apply to all pages.

Note: It's vital the code appears on every page, otherwise, you'll lose tracking data as users navigate your site, creating an incomplete and inaccurate picture of their journey.

How to Verify Your Google Analytics Installation

After installing the code, you should confirm it's working. Don't just set it and forget it! Here's the easiest way to check:

Check the Realtime Report

Go to your Google Analytics dashboard.
In the left-hand navigation, go to Reports > Realtime. This report shows you activity on your site as it's happening.
Open your own website in a new, separate browser window (using incognito mode is a good practice to ensure you're not logged in as an admin).
Wait about 30 seconds. In the GA Realtime report, you should see the number of "Users in last 30 minutes" change to at least 1. You should also see activity populate on the map and in the other cards.

If you see your visit, congratulations - your tracking code is working perfectly!

Universal Analytics vs. GA4: A Quick Note

You may see older articles mentioning a tracking code that starts with "UA-". This was for Universal Analytics, the previous version of Google Analytics, which was officially discontinued in July 2023. All users should now be using the new GA4, which uses the "G-" Measurement ID and the gtag.js snippet.

While the goal is the same - to track website activity - the underlying methodology is different. GA4 is built for the modern internet, focusing on "events" (like a click or scroll) rather than just "sessions" (a grouped collection of pageviews). The GA4 code snippet is more powerful and flexible, paving the way for better cross-device and cross-platform tracking.

Final Thoughts

The Google Analytics code is an absolutely essential tool for anyone with a website. It’s a small, unassuming bit of JavaScript that serves as your direct line to understanding your audience, measuring marketing effectiveness, and finding opportunities to improve your visitor experience. Installing it correctly is the critical first step in making informed, data-driven decisions that grow your business.

Getting the code installed is step one, but transforming that raw data into clear, actionable reports is often the hardest part. Instead of getting tangled up in complex reporting menus, we built Graphed to do the heavy lifting for you. You can connect your Google Analytics account in seconds and then use simple, plain English to ask for the exact charts and dashboards you need, giving you instant answers without the manual work.