The file crc32.js provides crc32(), an efficient implementation of the CRC32 algorithm that will produce the same result as PHP's crc32() function.

To be able to compare output from JS and PHP, the PHP version must be used on a string encoded with UTF-8 and the result must be printed using printf('%u') or sprintf('%u') since it is an unsigned integer. The file crc32.php includes example PHP code.