PHP Cookies

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Cookies of PHP enable a website store small bits of data on your computer machine in your web browser. Cookies are used to enable PHP to remember various things like user personalized settings and saved login data and browsing history.

Unlike sessions, cookies save the information on the client side, not the server. As a result, developers typically choose to store in cookies only non sensitive and ‘safe’ data that can increase the ‘user friendly’ experince.

Why PHP Cookies Are Important

PHP cookies makes a website more personal. A website is able to remember users’ language selection, or set website theme, so the user won ‘t need to do it every time.

Without these cookies, it would be necessary for users to repeat the same procedure each time they visit a site. This would lead to an uncomfortable and slow browsing.

How PHP Cookies Work

The life cycle of PHP cookies is fairly simple.

The first thing PHP does is create a cookie with a name and a value.
Next, cookie is sent by the server to the browser.
Then, the browser stores the cookie on the user‘s machine.
Next, the browser will send the cookie along in subsequent requests.

As a result of this, PHP is able to identify users upon their return to the site.

Creating a Cookie in PHP

You can also set a cookie by using the setcookie() function.

<?php
setcookie("username", "Varsha", time() + 3600);
?>

This cookie will expire in an hour. After that it‘ll expire empty.

Accessing a Cookie in PHP

Once a cookie is set you can read the value using the $_COOKIE variable.

<?php
echo $_COOKIE['username'];
?>

Remember that cookies are only available after the page refresh.

Deleting a Cookie in PHP

To delete a cookie, you need to assign a value for the expiry time of the cookie which needs to be in the past.

<?php
setcookie("username", "", time() - 3600);
?>

This action instructs the browser to delete the cookie.

Common Use Cases of PHP Cookies

Most of the PHP cookies are beneficial at everyday life usages.

Remembering User Preferences

Cookies remember the settings (for example language, theme, font size). It makes the website more accustomed when people come back.

“Remember Me” Feature

Certain login systems keep cookies to avoid users having to repeatkeying their email or choice of login.

Tracking User Activity

Cookies are used to keep track of pages viewed or items looked at recently by a user.

Saving Form Data

Cookies also prevent form input being lost if the page refreshes unexpectedly.

PHP Cookies vs PHP Sessions

Feature	Cookies	Sessions
Storage location	Browser	Server
Security	Lower	Higher
Data size	Small	Large
Expiry	Time based	Logout or timeout
Best use	Preferences	Login systems

Knowing this difference helps you decide which option to use.

Common Beginner Mistakes

Storing passwords in Cookies
Failing to add an expiry time
Attempting to set cookies before page has reloaded
Cookies for internal purposes

By avoiding these mistakes’ safety and performance will be improved.

Best Practices for PHP Cookies

Save only safe information
Always chose an expiry time
Only use cookies if absolutely necessary
Use sessions to store data securely
Verify cookie values before using them

Summary

Cookies are used by PHP to remember users by storing small bits of data in the visitor‘s browser. They are effective for preferences, tracking and convenience options. Correct implementation of cookies can give a user everything they need without any security concerns.