doesnt round trip even 10 places

[jeacott1]

var Base62=require('base62');
var maxv= Base62.decode("ZZZZZZZZZZ");
var mmaxv = Base62.encode(maxv);
console.log("maxv=" +maxv+" mmaxv="+mmaxv);


>   maxv=839299365868340200 mmaxv=10000000000

[kchapelier]

This is due to the numbers being represented in JavaScript as IEEE 754 double-precision binary floating-point (wiki) thus being only able to precisely represent integers up to 53 bits long (the value of Number.MAX_SAFE_INTEGER, or Math.pow(2, 53) - 1).

The only way to bypass that would be to use custom number representation such as the bignum and big-integer modules. Some other base64 modules (b64) base62 modules (b62) are doing just that, but it comes at a cost.