mt_rand Generate a random value via the Mersenne Twister Random Number Generator &reftitle.description; intmt_rand intmt_rand intmin intmax &caution.cryptographically-insecure; Many random number generators of older libcs have dubious or unknown characteristics and are slow. The mt_rand function is a drop-in replacement for the older rand. It uses a random number generator with known characteristics using the Mersenne Twister, which will produce random numbers four times faster than what the average libc rand() provides. If called without the optional min, max arguments mt_rand returns a pseudo-random value between 0 and mt_getrandmax. If you want a random number between 5 and 15 (inclusive), for example, use mt_rand(5, 15). &reftitle.parameters; min Optional lowest value to be returned (default: 0) max Optional highest value to be returned (default: mt_getrandmax) &reftitle.returnvalues; A random integer value between min (or 0) and max (or mt_getrandmax, inclusive), or &false; if max is less than min. &reftitle.changelog; &Version; &Description; 7.2.0 mt_rand has received a bug fix for a modulo bias bug. This means that sequences generated with a specific seed may differ from PHP 7.1 on 64-bit machines. 7.1.0 rand has been made an alias of mt_rand. 7.1.0 mt_rand has been updated to use the fixed, correct, version of the Mersenne Twister algorithm. To fall back to the old behaviour, use mt_srand with MT_RAND_PHP as the second parameter. 5.3.4 Issues an E_WARNING and returns &false; if max < min. &reftitle.examples; ]]> &example.outputs.similar; &reftitle.notes; min max range must be within the range mt_getrandmax. i.e. (max - min) <= mt_getrandmax Otherwise, mt_rand may return poorer random numbers than it should. &reftitle.seealso; mt_srand mt_getrandmax random_int random_bytes openssl_random_pseudo_bytes rand