var pw = "ksn73ADkdfdd"; var regex = /^(?=(.*[A-Z]){1})(?=(.*[a-z]){1})(?=(.*\d){1}).{8,15}$/; // ^.* = start // (?=(.*[A-Z]){1}) = min. 1 uppercases // (?=(.*[a-z]){1}) = min. 1 Lowercases // (?=(.*\d){1}) = min. 1 Numbers // .{8,15}$ = min. 8 and max. 15 chars console.log(regex.test(pw)); // source https://stackoverflow.com/a/33051728/4324393