How to Use Cookies in PHP in 2025

Cookies play a critical role in web applications, allowing developers to store and retrieve small pieces of data on the client’s browser. As we approach 2025, understanding how to effectively utilize cookies in PHP will remain essential for optimized web application performance. In this article, we’ll cover how to use cookies in PHP and explore best practices to ensure that your applications are secure, efficient, and user-friendly.

What are Cookies?

Cookies are small data files stored on users’ browsers. They are used to remember stateful information and track user activities for an enhanced browsing experience. In PHP, cookies are simple to implement and manipulate, offering a handy way of maintaining sessions and user preferences.

Setting a Cookie in PHP

To set a cookie in PHP, you use the setcookie() function. This function should be called before any output is sent to the browser. Here’s a simple example:

<?php
// Set a cookie named "user" with the value "John Doe" that expires in 30 days
setcookie("user", "John Doe", time() + (86400 * 30), "/"); // 86400 = 1 day
?>

In this example, the cookie user will persist for 30 days. The path / means that the cookie is available across the entire domain.

Accessing Cookies in PHP

To access a cookie in PHP, you can use the superglobal $_COOKIE array. Here’s how you can retrieve the value of the user cookie we set previously:

<?php
if(isset($_COOKIE["user"])) {
    echo "User is: " . $_COOKIE["user"];
} else {
    echo "User is not set.";
}
?>

Deleting a Cookie

Deleting a cookie in PHP requires setting the expiration date to a past time, along with the same parameters used when you set it. Here’s how:

<?php
// Delete a cookie named "user"
setcookie("user", "", time() - 3600, "/");
?>

Best Practices for Cookie Management in PHP

1. Security: Always use the httponly and secure flags when setting cookies. This prevents cookies from being accessed via JavaScript and ensures they are only transmitted over HTTPS.

   setcookie("user", "John Doe", time() + (86400 * 30), "/", "", true, true);
   

   1. Validation: Validate cookie values before using them, as they can be modified by users.

   2. Encryption: Encrypt sensitive data within cookies to prevent data breaches.

      Advanced Implementations

      For more advanced PHP implementation tasks like PHP integration with PowerShell, sending UDP packets in PHP, or executing scripts, check out our various guides. Additionally, learn how to handle emails in frameworks such as CakePHP via our CakePHP email sending guide. By adhering to these practices and exploring related technologies, PHP developers can maintain modern, efficient, and secure web applications well into 2025 and beyond. For script execution techniques, refer to our comprehensive article on executing scripts from PHP.