How to Set Cookie Expiration in PHP: Simple Guide

In PHP, you set cookie expiration by passing the expiration time as a Unix timestamp to the setcookie() function's third parameter. Use time() + seconds to specify how long the cookie should last, for example, time() + 3600 for one hour.

Syntax

The setcookie() function sets a cookie with optional parameters. The third parameter is the expiration time, given as a Unix timestamp (seconds since January 1, 1970). If you want the cookie to expire in the future, add the number of seconds to time(). If you set it to 0 or omit it, the cookie expires when the browser closes.

• name: The cookie's name.
• value: The cookie's value.
• expire: Expiration time as Unix timestamp.
• path: Path on the server where the cookie is available.
• domain: Domain that can access the cookie.
• secure: If true, cookie sent over HTTPS only.
• httponly: If true, cookie not accessible via JavaScript.

php

setcookie(string $name, string $value = "", int $expire = 0, string $path = "", string $domain = "", bool $secure = false, bool $httponly = false): bool

Example

This example sets a cookie named user with value John that expires in 1 hour (3600 seconds). It shows how to set the expiration time using time() + 3600.

php

<?php
// Set cookie 'user' to 'John' that expires in 1 hour
setcookie('user', 'John', time() + 3600);

// Confirm cookie is set
if (isset($_COOKIE['user'])) {
    echo 'Cookie user is set with value: ' . $_COOKIE['user'];
} else {
    echo 'Cookie user is not set yet.';
}
?>

Output

Cookie user is not set yet.

Common Pitfalls

Common mistakes when setting cookie expiration include:

• Setting expiration time in the past or as a string instead of a Unix timestamp.
• Calling setcookie() after outputting HTML or whitespace, which causes headers to be sent too late.
• Forgetting that cookies set in the current request are not available until the next page load.

Always call setcookie() before any output and use time() + seconds for expiration.

php

<?php
// Wrong: expiration as string (does not work as expected)
setcookie('test', 'value', '3600'); // Wrong

// Right: expiration as Unix timestamp
setcookie('test', 'value', time() + 3600); // Correct

// Wrong: calling after output
echo 'Hello';
setcookie('test2', 'value2', time() + 3600); // Warning: headers already sent
?>

Quick Reference

Summary tips for setting cookie expiration in PHP:

• Use time() + seconds for expiration time.
• Set expiration to 0 or omit for session cookies (expire on browser close).
• Call setcookie() before any output.
• Remember cookies are available on next page load, not immediately.

Key Takeaways

Use time() + seconds to set cookie expiration as a Unix timestamp.

Call setcookie() before sending any output to avoid header errors.

Cookies set in the current request are available only on the next page load.

Set expiration to 0 or omit it for session cookies that expire on browser close.

Always use integer timestamps, not strings, for the expiration parameter.