How to Implement Google Login in PHP Using OAuth 2.0 (Step-by-Step Guide)

Why Add Google Login to Your PHP Application?

              Adding Google Login (also called "Sign in with Google") to your PHP app is one of the easiest ways to provide secure, fast authentication.

Users don't need to create new accounts—they simply use their existing Google credentials. This approach:

• Reduces friction during sign-up and login
• Boosts conversion rates
• Leverages Google's robust security features

Table Of Content

1 Prerequisites

• PHP 8.0+ (recommended; works with 7.4+)
• Composer installed
• A Google account
• Local server (e.g., XAMPP, Laravel Valet, or PHP built-in server)

2 What This Tutorial Covers

In this updated tutorial, we'll use the official Google API Client Library for PHP to implement server-side Google OAuth 2.0 authentication.

Key features of this implementation:

• No database required (ideal for quick prototypes or simple apps)
• User information stored securely in PHP sessions
• Follows current Google OAuth 2.0 best practices (as of 2026)

This method is straightforward, production-ready with minor enhancements (like adding HTTPS and token validation), and remains fully supported using the official library (latest version ~2.19.0).

3 Create Project Folder "google-login-app"

Create Project Folder "google-login-app" in root directory store all project files

4 Install Google Client Library

First, make sure your computer has a composer.
Use the following command to install Google Client Library via Composer.

composer require google/apiclient:^2.0

This command will download the google api client Library and add it to your project.

5 Create Google API Console Project

5.1 Login into Google Developer Account

If you have Google Developer Account Go to https://console.cloud.google.com/, else you can easily create one directly from the Google Developers Console.

5.2 Create New Project

Create a Project in the Google Developer Console


Entering Project information in the following Screen


Project successfully created with given information's

5.3 Create Credentials

Now Create the credential by choosing "Credentials" in the side bar, click "Create Credentials" button and choose "OAuth Client ID".

5.4 Configure Consent Screen

Now Click "Configure Consent Screen" Button.


It will redirected to the following screen and choose "External" option then create.

5.5 Update App Information

By providing App and Developer Information Complete the form then click "Save and Continue" Button.

5.6 OAuth Client Created

Now Create the OAuth Client by choosing "Credentials" in the side bar, click "Create Credentials" button and choose "OAuth Client ID".


It will redirected to the following screen and fill the detail about our app and fill the authorized redirect URIs. This is the URI that we will use to redirect user after they choose their Google account to login to our web. For example here I use http://localhost/google-signin-app/google-callback.php for the callback URI..


Now we get the Client ID and the Client Secret.

6 Configure Google App Credentials(config.php)

Insert the Client ID and Client Secret key and redirect URI into the config.php file, Which we obtained from previous step GOOGLE_CLIENT_ID and GOOGLE_CLIENT_SECRET. Additionally, include a new key in the config.php file called GOOGLE_REDIRECT_URI and populate it with the callback URI used in the Google API Console.

<?php
// config.php - NEVER commit this file to Git in production!

define('GOOGLE_CLIENT_ID',     'YOUR_CLIENT_ID_HERE.apps.googleusercontent.com');
define('GOOGLE_CLIENT_SECRET', 'YOUR_CLIENT_SECRET_HERE');
define('GOOGLE_REDIRECT_URI',  'http://localhost/google-login-php/google-callback.php');

// Optional: for production, use .env file or environment variables instead

7 Create Login Page - login.php

Create a simple login page (login.php) that includes a "Login with Google" button: google-login-app/login.php

<?php
// login.php
require_once 'vendor/autoload.php';
require_once 'config.php';

$client = new Google_Client();
$client->setClientId(GOOGLE_CLIENT_ID);
$client->setClientSecret(GOOGLE_CLIENT_SECRET);
$client->setRedirectUri(GOOGLE_REDIRECT_URI);
$client->addScope(['email', 'profile']);

$authUrl = $client->createAuthUrl();
?>
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Login with Google - PHP Demo</title>
    <style>
        body { font-family: Arial, sans-serif; text-align: center; padding: 80px 20px; background: #f4f4f4; }
        h1 { color: #333; }
        .google-btn {
            display: inline-block;
            background: #4285F4;
            color: white;
            padding: 14px 28px;
            border-radius: 4px;
            text-decoration: none;
            font-size: 18px;
            font-weight: bold;
            margin-top: 20px;
        }
        .google-btn:hover { background: #3267D6; }
    </style>
</head>
<body>
    <h1>Welcome! Sign in with Google</h1>
    <p>Use your Google account to log in securely — no new password needed.</p>
    <a href="<?= htmlspecialchars($authUrl) ?>" class="google-btn">Login with Google</a>
</body>
</html>

8 Create Google Callback Page - google-callback.php (Handles Google response)

Create a file (google-callback.php) to handle the callback from Google after authentication google-login-app/google-callback.php

<?php
// google-callback.php
session_start();
require_once 'vendor/autoload.php';
require_once 'config.php';

$client = new Google_Client();
$client->setClientId(GOOGLE_CLIENT_ID);
$client->setClientSecret(GOOGLE_CLIENT_SECRET);
$client->setRedirectUri(GOOGLE_REDIRECT_URI);

if (isset($_GET['code'])) {
    try {
        $token = $client->fetchAccessTokenWithAuthCode($_GET['code']);
        if (isset($token['error'])) {
            throw new Exception($token['error_description']);
        }

        $client->setAccessToken($token);

        $googleService = new Google_Service_Oauth2($client);
        $userInfo = $googleService->userinfo->get();

        // Store minimal user data in session (in production: save to database, check for existing user, etc.)
        $_SESSION['google_id']   = $userInfo->id;
        $_SESSION['email']       = $userInfo->email;
        $_SESSION['name']        = $userInfo->name;
        $_SESSION['picture']     = $userInfo->picture ?? '';

        header('Location: dashboard.php');
        exit;
    } catch (Exception $e) {
        echo "Error during authentication: " . htmlspecialchars($e->getMessage());
        echo '<br><a href="login.php">Back to login</a>';
        exit;
    }
} else {
    // No code → error or direct access
    echo "Authentication failed or access denied.";
    echo '<br><a href="login.php">Try again</a>';
}

9 Create Dashboard - dashboard.php

Create a simple secured page (dashboard.php) that only logged-in users can access: google-login-app/dashboard.php

<?php
// dashboard.php
session_start();

if (!isset($_SESSION['google_id'])) {
    header('Location: login.php');
    exit;
}
?>
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Dashboard - Logged In</title>
    <style>
        body { font-family: Arial, sans-serif; max-width: 600px; margin: 40px auto; padding: 20px; background: #fff; border-radius: 8px; box-shadow: 0 2px 10px rgba(0,0,0,0.1); }
        img { border-radius: 50%; margin: 20px 0; }
        a { color: #d32f2f; text-decoration: none; font-weight: bold; }
    </style>
</head>
<body>
    <h1>Hello, <?= htmlspecialchars($_SESSION['name'] ?? 'User') ?>!</h1>

    <p><strong>Email:</strong> <?= htmlspecialchars($_SESSION['email']) ?></p>
    <p><strong>Google ID:</strong> <?= htmlspecialchars($_SESSION['google_id']) ?></p>

    <?php if (!empty($_SESSION['picture'])): ?>
        <img src="<?= htmlspecialchars($_SESSION['picture']) ?>" alt="Profile Picture" width="120" height="120">
    <?php endif; ?>

    <p><a href="logout.php">Logout</a></p>
</body>
</html>

10 Implement Logout Functionality

Create a logout page (logout.php) to destroy the session and log the user out: google-signin-app/logout.php

<?php
// logout.php
session_start();
session_destroy();
header('Location: login.php');
exit;

11 Folder Structure

12 Run Web Server to Test the App

• Start your local server:
  XAMPP / WAMP → start Apache
  Or command line: php -S localhost:8000
• Visit: http://localhost/google-login-php/login.php (adjust port/folder)
• Click "Login with Google" → approve → see your details on dashboard.

Common Issues & Fixes

• Redirect URI mismatch: Ensure the URI in code matches Google Console exactly (including http/https, trailing slash, port).
• Invalid grant: Refresh token issues—usually caused by reusing old codes.
• Production tips: Use HTTPS, store tokens securely, add database integration for persistent logins, consider revocation on logout.

13 Conclusion

You've now implemented a secure Google Login system in PHP! This method follows official Google OAuth 2.0 best practices and is production-ready with minor enhancements (e.g., database + PKCE). For advanced use cases, explore Google Identity Services or frameworks like Laravel Socialite.

Frequently Asked Questions