Add Login with Google to Your PHP Website

<?php
define('GOOGLE_CLIENT_ID',     'YOUR_CLIENT_ID.apps.googleusercontent.com');
define('GOOGLE_CLIENT_SECRET', 'YOUR_CLIENT_SECRET');
define('GOOGLE_REDIRECT_URI',  'https://www.yourdomain.com/auth/google-callback.php');

<?php
session_start();
require_once 'google-config.php';

// Database connection
$conn = new mysqli("localhost", "db_user", "••••••••", "db_name");

// Step 1: Redirect to Google if no code
if (!isset($_GET['code'])) {
    $params = [
        'client_id'     => GOOGLE_CLIENT_ID,
        'redirect_uri'  => GOOGLE_REDIRECT_URI,
        'response_type' => 'code',
        'scope'         => 'email profile',
        'access_type'   => 'online',
    ];
    $url = 'https://accounts.google.com/o/oauth2/auth?'
           . http_build_query($params);
    header('Location: ' . $url);
    exit;
}

// Step 2: Exchange code for access token
$tokenData = [
    'code'          => $_GET['code'],
    'client_id'     => GOOGLE_CLIENT_ID,
    'client_secret' => GOOGLE_CLIENT_SECRET,
    'redirect_uri'  => GOOGLE_REDIRECT_URI,
    'grant_type'    => 'authorization_code',
];
$ch = curl_init('https://oauth2.googleapis.com/token');
curl_setopt($ch, CURLOPT_POST, true);
curl_setopt($ch, CURLOPT_POSTFIELDS, http_build_query($tokenData));
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
$tokenResponse = json_decode(curl_exec($ch), true);
curl_close($ch);

if (!isset($tokenResponse['access_token'])) {
    header('Location: /login.php?error=token_failed');
    exit;
}

// Step 3: Get user info from Google
$ch = curl_init('https://www.googleapis.com/oauth2/v2/userinfo');
curl_setopt($ch, CURLOPT_HTTPHEADER,
    ['Authorization: Bearer ' . $tokenResponse['access_token']]);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
$userInfo = json_decode(curl_exec($ch), true);
curl_close($ch);

$google_id = $userInfo['id'];
$email     = $userInfo['email'];
$name      = $userInfo['name'];
$avatar    = $userInfo['picture'];

// Step 4: Auto-create table & save user
$conn->query("CREATE TABLE IF NOT EXISTS gmails (
    id INT AUTO_INCREMENT PRIMARY KEY,
    google_id VARCHAR(100) UNIQUE,
    name VARCHAR(150),
    email VARCHAR(150) UNIQUE,
    avatar VARCHAR(500),
    created_at DATETIME DEFAULT CURRENT_TIMESTAMP
)");

$stmt = $conn->prepare(
    "SELECT id, name FROM gmails WHERE google_id=? OR email=?");
$stmt->bind_param("ss", $google_id, $email);
$stmt->execute();
$result = $stmt->get_result();

if ($result->num_rows > 0) {
    $user = $result->fetch_assoc();
} else {
    $stmt2 = $conn->prepare(
        "INSERT INTO gmails (google_id,name,email,avatar) VALUES (?,?,?,?)");
    $stmt2->bind_param("ssss",
        $google_id, $name, $email, $avatar);
    $stmt2->execute();
    $user = ['id' => $conn->insert_id, 'name' => $name];
}

// Step 5: Set session & redirect
$_SESSION['user_id']    = $user['id'];
$_SESSION['user_name']  = $user['name'] ?? $name;
$_SESSION['user_email'] = $email;
$_SESSION['avatar']     = $avatar;

header('Location: /index.php');
exit;

<?php
session_start();
require_once 'auth/google-config.php';

$params = [
    'client_id'     => GOOGLE_CLIENT_ID,
    'redirect_uri'  => GOOGLE_REDIRECT_URI,
    'response_type' => 'code',
    'scope'         => 'email profile',
    'access_type'   => 'online',
];
$googleLoginUrl = 'https://accounts.google.com/o/oauth2/auth?'
                  . http_build_query($params);

require_once 'includes/head.php';
?>

<main class="container">
  <div class="card shadow-lg border-0 mx-auto"
       style="max-width:450px;margin-top:80px;margin-bottom:80px;">
    <div class="card-body p-5">
      <div class="text-center mb-4">
        <i class="bi bi-person-circle" style="font-size:3rem;color:#0d6efd;"></i>
        <h2 class="fw-bold mt-2">Sign In</h2>
        <p class="text-muted">Use your Google account to continue</p>
      </div>
      <div class="d-grid">
        <a href="<?= $googleLoginUrl ?>"
           class="btn btn-outline-dark btn-lg d-flex align-items-center
                  justify-content-center gap-3">
          <img src="https://developers.google.com/identity/images/g-logo.png"
               width="24" height="24">
          <span class="fw-bold">Continue with Google</span>
        </a>
      </div>
    </div>
  </div>
</main>

<?php if (isset($_SESSION['user_id'])): ?>
  <!-- Logged in -->
  <div class="d-flex align-items-center gap-2">
    <img src="<?= htmlspecialchars($_SESSION['avatar']) ?>"
         width="36" height="36" class="rounded-circle border">
    <span class="fw-semibold">
      <?= htmlspecialchars($_SESSION['user_name']) ?>
    </span>
    <a href="/logout.php" class="btn btn-outline-danger btn-sm">Logout</a>
  </div>
<?php else: ?>
  <!-- Not logged in -->
  <a href="/login.php" class="btn btn-outline-dark">Login</a>
<?php endif; ?>

<?php
// Simple key protection
$admin_pass = "your_secret_key";
if (!isset($_GET['key']) || $_GET['key'] !== $admin_pass) {
    die("<h3 style='color:red'>Access Denied</h3>");
}

// Download emails as .txt
if (isset($_GET['download'])) {
    $result2 = $conn->query("SELECT email FROM gmails");
    $emails = [];
    while ($row = $result2->fetch_assoc())
        $emails[] = $row['email'];
    header('Content-Type: text/plain');
    header('Content-Disposition: attachment; filename="emails.txt"');
    echo implode(', ', $emails);
    exit;
}

https://www.yourdomain.com/gmail-list.php?key=your_secret_key

CREATE TABLE page_views (
  id INT AUTO_INCREMENT PRIMARY KEY,
  user_id INT,
  email VARCHAR(150),
  page VARCHAR(300),
  visited_at DATETIME DEFAULT CURRENT_TIMESTAMP
);

if (isset($_SESSION['user_id'])) {
    $uid   = $_SESSION['user_id'];
    $email = $_SESSION['user_email'];
    $page  = $_SERVER['REQUEST_URI'];
    $conn->query(
        "INSERT INTO page_views (user_id,email,page)
         VALUES ('$uid','$email','$page')"
    );
}