Here’s a detailed 2000+ word guide on fetching Google Analytics 4 (GA4) data in PHP with API authentication, data retrieval, troubleshooting, and advanced use cases.

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How to Fetch Google Analytics 4 (GA4) Data in PHP Using the API

Introduction

Google Analytics 4 (GA4) is a powerful analytics tool designed to help website owners track user behavior, page performance, and conversion rates. Unlike Universal Analytics, GA4 uses an event-driven model, allowing for more detailed insights.

If you want to fetch GA4 data in PHP, the best way is through the Google Analytics Data API. This enables you to pull key metrics such as page views, user sessions, top traffic sources, and engagement rates directly into your application.

In this comprehensive guide, we’ll walk through:
✅ Setting up API authentication
✅ Installing the Google Analytics PHP client
✅ Fetching data for the last 7 and 28 days
✅ Displaying GA4 reports in PHP
✅ Troubleshooting common API errors
✅ Advanced use cases

Let’s get started!

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1. Setting Up Google Analytics API Credentials

Before you can fetch GA4 data in PHP, you need to:

1. Enable Google Analytics Data API in the Google Cloud Console
2. Create a service account and download a JSON key
3. Grant API permissions in Google Analytics Admin

Step 1: Enable Google Analytics Data API

1. Go to Google Cloud Console
2. Select an existing project or create a new one
3. Navigate to APIs & Services > Library
4. Search for Google Analytics Data API
5. Click Enable API

Step 2: Create Service Account & Download JSON Key

1. In Google Cloud Console, go to APIs & Services > Credentials
2. Click Create Credentials > Service Account
3. Enter a name, then click Create & Continue
4. Assign the Editor role and click Done
5. Open the new service account, go to Keys, and click Add Key > JSON
6. Download the JSON file (important for authentication)

Step 3: Grant GA4 API Permissions

1. Go to Google Analytics
2. Navigate to Admin > Account Settings
3. Click Account Access Management > Add User
4. Use the service account email from the JSON file
5. Assign the role Viewer (or Editor if needed)
6. Click Add

✅ Done! You’re now ready to use the GA4 API with PHP.

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2. Install the Google Analytics API Client for PHP

To interact with GA4, we need the official Google Analytics Data API client.

Install via Composer

Run the following command in your project directory:

composer require google/analytics-data

This will install the Google API PHP client library, allowing us to query GA4 data.

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3. Fetching GA4 Data in PHP

Now let’s fetch GA4 analytics data using PHP.

Basic Setup in index.php

<?php

require 'vendor/autoload.php';

use Google\Analytics\Data\V1beta\BetaAnalyticsDataClient;
use Google\Analytics\Data\V1beta\Metric;
use Google\Analytics\Data\V1beta\Dimension;
use Google\Analytics\Data\V1beta\DateRange;
use Google\Analytics\Data\V1beta\RunReportRequest;

// Load authentication credentials
putenv('GOOGLE_APPLICATION_CREDENTIALS=' . __DIR__ . '/your-credentials.json');

// Your GA4 Property ID
$property_id = 'YOUR_GA4_PROPERTY_ID';

// Initialize Google Analytics Client
$client = new BetaAnalyticsDataClient();

// Function to fetch active users in last 7 days
function getActiveUsersLast7Days($client, $property_id) {
    $response = $client->runReport([
        'property' => 'properties/' . $property_id,
        'dateRanges' => [
            new DateRange(['start_date' => '7daysAgo', 'end_date' => 'today'])
        ],
        'metrics' => [
            new Metric(['name' => 'activeUsers'])
        ]
    ]);

    foreach ($response->getRows() as $row) {
        return $row->getMetricValues()[0]->getValue();
    }
    return 0;
}

// Fetch active users in last 7 days
$usersLast7Days = getActiveUsersLast7Days($client, $property_id);
echo "<h2>Active Users (Last 7 Days): $usersLast7Days</h2>";

?>

How It Works

🔹 Authenticates with GA4 using the service account
🔹 Fetches the number of active users from the last 7 days
🔹 Displays the result in a PHP page

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4. Displaying Top Content Pages (Last 28 Days)

Want to see your top 10 most visited pages? Modify the script like this:

function getTopContentLast28Days($client, $property_id) {
    $response = $client->runReport([
        'property' => 'properties/' . $property_id,
        'dateRanges' => [
            new DateRange(['start_date' => '28daysAgo', 'end_date' => 'today'])
        ],
        'dimensions' => [new Dimension(['name' => 'pageTitle'])],
        'metrics' => [new Metric(['name' => 'screenPageViews'])],
        'limit' => 10
    ]);

    return $response->getRows();
}

// Fetch and display top content
$topContent = getTopContentLast28Days($client, $property_id);

echo "<h2>Top 10 Pages (Last 28 Days)</h2>";
foreach ($topContent as $row) {
    echo "<p><strong>{$row->getDimensionValues()[0]->getValue()}</strong>: {$row->getMetricValues()[0]->getValue()} views</p>";
}

This will list the 10 most visited pages in the last 28 days.

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5. Fetching Data for Traffic Channels, Locations, and Devices

Pie Chart Data (Last 7 Days)

function getTrafficData($client, $property_id, $dimension) {
    $response = $client->runReport([
        'property' => 'properties/' . $property_id,
        'dateRanges' => [new DateRange(['start_date' => '7daysAgo', 'end_date' => 'today'])],
        'dimensions' => [new Dimension(['name' => $dimension])],
        'metrics' => [new Metric(['name' => 'activeUsers'])],
    ]);

    return $response->getRows();
}

// Fetch data for Channels, Locations, Devices
$channels = getTrafficData($client, $property_id, 'sessionDefaultChannelGrouping');
$locations = getTrafficData($client, $property_id, 'country');
$devices = getTrafficData($client, $property_id, 'deviceCategory');

echo "<h2>Traffic by Channels</h2>";
foreach ($channels as $row) {
    echo "<p>{$row->getDimensionValues()[0]->getValue()}: {$row->getMetricValues()[0]->getValue()} users</p>";
}

echo "<h2>Traffic by Country</h2>";
foreach ($locations as $row) {
    echo "<p>{$row->getDimensionValues()[0]->getValue()}: {$row->getMetricValues()[0]->getValue()} users</p>";
}

echo "<h2>Traffic by Device</h2>";
foreach ($devices as $row) {
    echo "<p>{$row->getDimensionValues()[0]->getValue()}: {$row->getMetricValues()[0]->getValue()} users</p>";
}

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6. Advanced Use Cases

✔ Track Real-Time Users using realtimeActiveUsers
✔ Fetch Conversion Data using eventCount
✔ Integrate with MySQL for Custom Analytics Dashboards

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Conclusion

Fetching Google Analytics 4 (GA4) data in PHP allows you to monitor website traffic, top content, and audience insights programmatically. By following this guide, you can build your own reporting tools and integrate GA4 metrics into your applications.

🚀 Next Steps:
✅ Add caching to store analytics data
✅ Display results in graphs using Chart.js
✅ Extend the API to fetch conversion data