setcookie()

setcookie() — Send a cookie.

Built-in function of PHP 8.5. The manual lists it as available in PHP 4, PHP 5, PHP 7, PHP 8. This page is the reference card: signature, parameters and return value, plus the changelog and the example the manual provides.

What it does

setcookie() defines a cookie to be sent along with the rest of the HTTP headers. Like other headers, cookies must be sent before any output from the script (this is a protocol restriction). This requires that this function is called prior to any output, including <html> and <head> tags as well as any whitespace.

Signature

setcookie(string $name, string $value = "", int $expires_or_options = 0, string $path = "", string $domain = "", bool $secure = false, bool $httponly = false): bool setcookie(string $name, string $value = "", array $options = []): bool

Parameters

Parameter	Type	What it takes
$name	string	The name of the cookie.
$value	string	The value of the cookie. This value is stored on the clients computer; do not store sensitive information. Assuming the name is 'cookiename', this value is retrieved through $_COOKIE['cookiename']
$expires_or_options	int	The time the cookie expires. This is a Unix timestamp so is in number of seconds since the epoch. One way to set this is by adding the number of seconds before the cookie should expire to the result of calling time(). For instance, time()+606024*30 will set the cookie to expire in 30 days. Another option is to use the mktime() function. If set to 0, or omitted, the cookie will expire at the end of the session ...
$path	string	The path on the server in which the cookie will be available on. If set to '/', the cookie will be available within the entire domain. If set to '/foo/', the cookie will only be available within the /foo/ directory and all sub-directories such as /foo/bar/ of domain. The default value is the current directory that the cookie is being set in.
$domain	string	The (sub)domain that the cookie is available to. Setting this to a subdomain (such as 'www.example.com') will make the cookie available to that subdomain and all other sub-domains of it (i.e. w2.www.example.com). To make the cookie available to the whole domain (including all subdomains of it), simply set the value to the domain name ('example.com', in this case).
$secure	bool	Indicates that the cookie should only be transmitted over a secure HTTPS connection from the client. When set to true, the cookie will only be set if a secure connection exists. On the server-side, it's on the programmer to send this kind of cookie only on secure connection (e.g. with respect to $_SERVER["HTTPS"]).
$httponly	bool	When true the cookie will be made accessible only through the HTTP protocol. This means that the cookie won't be accessible by scripting languages, such as JavaScript. It has been suggested that this setting can effectively help to reduce identity theft through XSS attacks (although it is not supported by all browsers), but that claim is often disputed. true or false
$options	array	An associative array which may have any of the keys expires, path, domain, secure, httponly, partitioned and samesite.

Return value

If output exists prior to calling this function, setcookie() will fail and return false. If setcookie() successfully runs, it will return true. This does not indicate whether the user accepted the cookie.

Example

A runnable snippet:

$value = 'something from somewhere'; // Set a "session cookie" that expires when the browser is closed setcookie("TestCookie", $value); // Set a cookie that expires in 1 hour setcookie("TestCookie", $value, time()+3600); // Set a cookie that applies only to a specific path on a specific domain // Note that the domain used should match the site domain setcookie("TestCookie", $value, time()+3600, "/~rasmus/", "example.com", true);

Changelog

Version	Change
8.5.0	The "partitioned" entry was added in the options array. If set to true, the cookie will be marked as Partitioned (CHIPS).
8.2.0	The date format of the cookie is now 'D, d M Y H:i:s \G\M\T'; previously it was 'D, d-M-Y H:i:s T'.
8.0.0	Passing unsupported keys now throws a ValueError instead of emitting an E_WARNING.
7.3.0	An alternative signature supporting an options array has been added. This signature supports also setting of the SameSite cookie attribute.