How to Generate Random Boolean Values in PHP?

You can generate a random boolean value in PHP using the mt_rand() function, and casting its result to a boolean like so:

// PHP 4+
$randBool = (bool) mt_rand(0, 1);

For more common cases, using mt_rand() is a good choice as it is typically faster than using more secure methods (such as with random_int(), etc.). However, for critical systems you might want to consider using the latter instead as the result of mt_rand() can be predicted.

Although you can use the rand() function instead of mt_rand() as well, it is recommended to use mt_rand() wherever possible as it uses the Mersenne Twister algorithm (which is considerably faster than rand()). Also, starting with PHP 7.1+, rand() is merely an alias of mt_rand().